[video_player] Fix Android lints (#3886)

Removes lint-baseline.xml and fixes all exposed lints. Includes an update of Pigeon to the latest version, to pick up warning fixes in generated code.

Part of flutter/flutter#88011

Author: stuartmorgan-g

packages/video_player/video_player_android/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.4.7
+
+* Fixes Java warnings.
+
 ## 2.4.6
 
 * Fixes compatibility with AGP versions older than 4.2.

packages/video_player/video_player_android/android/build.gradle

@@ -41,7 +41,6 @@ android {
         checkAllWarnings true
         warningsAsErrors true
         disable 'AndroidGradlePluginVersion', 'InvalidPackage', 'GradleDependency'
-        baseline file("lint-baseline.xml")
     }
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8

packages/video_player/video_player_android/android/lint-baseline.xml

@@ -13,8 +13,10 @@
 import javax.net.ssl.SSLSocket;
 import javax.net.ssl.SSLSocketFactory;
 
+// SSLSocketFactory does not have nullability annotations.
+@SuppressWarnings("UnknownNullness")
 public class CustomSSLSocketFactory extends SSLSocketFactory {
-  private SSLSocketFactory sslSocketFactory;
+  private final SSLSocketFactory sslSocketFactory;
 
   public CustomSSLSocketFactory() throws KeyManagementException, NoSuchAlgorithmException {
     SSLContext context = SSLContext.getInstance("TLS");