fix: remove do you want to download file.bin alert on iOS cp-7.61.0 (#23383)

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## **Description**
Remove "do you want to download file.bin" alert on iOS 
PR for react-native-webview-mm:
MetaMask/react-native-webview-mm#74

## **Changelog**

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CHANGELOG entry: Fixed a bug where we prompt do you want to download
file.bin alert

## **Related issues**

Fixes: #20359

## **Manual testing steps**

```gherkin
Feature: remove do you want to download file.bin alert 

  Scenario: user not seeing the alert
    Given user navigates to browser tab

    When user navigates to sites like https://adtech.org/metamask-iframe-example/
    Then user should not see an alert that says "do you want to download file.bin"
```

## **Screenshots/Recordings**

<!-- If applicable, add screenshots and/or recordings to visualize the
before and after of your change. -->

### **Before**
<img width="211" height="458" alt="Screenshot 2025-11-27 at 12 31 40 PM"
src="https://github.com/user-attachments/assets/0bfbd86f-1196-4320-b6f8-2dd499349437"
/>


### **After**
Not showing the alert
![iOS
after](https://github.com/user-attachments/assets/8b55ad4c-acf6-4de8-a303-215219d1b191)

Can still download files 

![downloads](https://github.com/user-attachments/assets/9c722df1-e6e6-4905-898c-e1775dce6915)

## **Pre-merge author checklist**

- [x] I’ve followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask Mobile
Coding
Standards](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [x] I've completed the PR template to the best of my ability
- [ ] I’ve included tests if applicable
- [ ] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [x] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

## **Pre-merge reviewer checklist**

- [x] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [x] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Suppresses the iOS "download File.bin" alert for data URLs and
consolidates Android WebView permission handling into a single dialog
with safer granting/cleanup.
> 
> - **iOS (RNCWebViewImpl)**:
> - Suppress downloads for `application/octet-stream` data URLs by
inferring extension early and ignoring `.bin`, preventing the "Do you
want to download File.bin" alert.
> - Minor refactor: compute `fileExtension` before decoding and reuse
it.
> - **Android (RNCWebChromeClient)**:
> - Rework permission flow: reset state, aggregate multiple permissions
into a single user prompt, map OS permissions to WebView resources, and
grant immediately when possible.
> - Add robust state cleanup and try/catch around `grant` to avoid
IllegalStateException; handle negative responses and pending system
permission requests correctly.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
59d75e8. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: weitingsun

.yarn/patches/@metamask-react-native-webview-npm-14.5.0-b34fed6d50.patch

@@ -152,3 +152,29 @@ index d1459423fe85502017d2b424f61718ce1ae082b1..7fda7cf056af3e7e8904a0e2aa3391dc
          }
 
          if (!pendingPermissions.isEmpty()) {
+diff --git a/apple/RNCWebViewImpl.m b/apple/RNCWebViewImpl.m
+index c3bb7cc41097a39964b56386dbde321f7d52b35a..ebbb771d6bba6182e03f3c96ae8c9ab6514bd4f9 100644
+--- a/apple/RNCWebViewImpl.m
++++ b/apple/RNCWebViewImpl.m
+@@ -973,11 +973,20 @@ -(void)setKeyboardDisplayRequiresUserAction:(BOOL)keyboardDisplayRequiresUserAct
+ }
+ 
+ - (void)downloadBase64File:(NSString *)base64String {
++    // Infer file extension from the data: URL before doing any heavy work.
++    // For generic application/octet-stream payloads we suppress the download
++    // entirely (no "Do you want to download File.bin?" alert), since these
++    // are typically iframe-driven noise rather than user‑initiated downloads.
++    NSString *fileExtension = [self fileExtensionFromBase64String:base64String];
++    if ([[fileExtension lowercaseString] isEqualToString:@"bin"]) {
++        NSLog(@"RNCWebViewImpl: Ignoring generic binary download (File.bin) from data: URL");
++        return;
++    }
++
+     NSArray *components = [base64String componentsSeparatedByString:@","];
+     NSString *base64ContentPart = components.lastObject;
+ 
+     NSData *fileData = [[NSData alloc] initWithBase64EncodedString:base64ContentPart options:NSDataBase64DecodingIgnoreUnknownCharacters];
+-    NSString *fileExtension = [self fileExtensionFromBase64String:base64String];
+     [self showDownloadAlert:fileExtension invokeDownload:^{
+     	NSString *tempFilePath = [NSTemporaryDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"File.%@", fileExtension]];
+         [fileData writeToFile:tempFilePath atomically:YES];

yarn.lock

@@ -9357,14 +9357,14 @@ __metadata:
 
 "@metamask/react-native-webview@patch:@metamask/react-native-webview@npm%3A14.5.0#~/.yarn/patches/@metamask-react-native-webview-npm-14.5.0-b34fed6d50.patch":
   version: 14.5.0
-  resolution: "@metamask/react-native-webview@patch:@metamask/react-native-webview@npm%3A14.5.0#~/.yarn/patches/@metamask-react-native-webview-npm-14.5.0-b34fed6d50.patch::version=14.5.0&hash=c64f43"
+  resolution: "@metamask/react-native-webview@patch:@metamask/react-native-webview@npm%3A14.5.0#~/.yarn/patches/@metamask-react-native-webview-npm-14.5.0-b34fed6d50.patch::version=14.5.0&hash=c6e87d"
   dependencies:
     escape-string-regexp: "npm:^4.0.0"
     invariant: "npm:2.2.4"
   peerDependencies:
     react: "*"
     react-native: "*"
-  checksum: 10/ea801ba7e33c39df045bbe6dd882792b96b89f32b391c7a46c1a2878a5987f275549682b308c7014fba46fc07d1c5605b0499c0425d21076c98f65bb4bb56b05
+  checksum: 10/f22bae5e15763e77ec0e21f34b31d97a48fadb35590a5e75341c93b269cbdb702fcafb4bd7d4b9041977ca525b03b49b558a3800126faadf08e64b8787fb1cb3
   languageName: node
   linkType: hard