camera_android: Camera.java pausePreview null check (#5265)

Fix: Check `captureSession` before call to stopRepeating in pausePreview.

[camera_android] sometimes crashes on pausePreview [#137544](flutter/flutter#137544)

*If you had to change anything in the [flutter/tests] repo, include a link to the migration guide as per the [breaking change policy].*

Author: PROGrand

packages/camera/camera_android/CHANGELOG.md

@@ -1,5 +1,7 @@
-## NEXT
+## 0.10.8+14
 
+* Fixes `pausePreview` null pointer error. `pausePreview` should not be called 
+  when camera is closed or not configured.
 * Updates minimum supported SDK version to Flutter 3.10/Dart 3.0.
 
 ## 0.10.8+13

packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/Camera.java

@@ -1076,8 +1076,13 @@ public void unlockCaptureOrientation() {
 
   /** Pause the preview from dart. */
   public void pausePreview() throws CameraAccessException {
-    this.pausedPreview = true;
-    this.captureSession.stopRepeating();
+    if (!this.pausedPreview) {
+      this.pausedPreview = true;
+
+      if (this.captureSession != null) {
+        this.captureSession.stopRepeating();
+      }
+    }
   }
 
   /** Resume the preview from dart. */

packages/camera/camera_android/android/src/test/java/io/flutter/plugins/camera/CameraTest.java

@@ -1165,6 +1165,19 @@ public void close_doesNotCloseCaptureSessionWhenCameraDeviceNonNull() {
     verify(mockCaptureSession, never()).close();
   }
 
+  @Test
+  public void pausePreview_doesNotCallStopRepeatingWhenCameraClosed() throws CameraAccessException {
+    ArrayList<CaptureRequest.Builder> mockRequestBuilders = new ArrayList<>();
+    mockRequestBuilders.add(mock(CaptureRequest.Builder.class));
+    CameraDeviceWrapper fakeCamera = new FakeCameraDeviceWrapper(mockRequestBuilders);
+    TestUtils.setPrivateField(camera, "cameraDevice", fakeCamera);
+
+    camera.close();
+    camera.pausePreview();
+
+    verify(mockCaptureSession, never()).stopRepeating();
+  }
+
   private static class TestCameraFeatureFactory implements CameraFeatureFactory {
     private final AutoFocusFeature mockAutoFocusFeature;
     private final ExposureLockFeature mockExposureLockFeature;

packages/camera/camera_android/pubspec.yaml

@@ -3,7 +3,7 @@ description: Android implementation of the camera plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/camera/camera_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+camera%22
 
-version: 0.10.8+13
+version: 0.10.8+14
 
 environment:
   sdk: ">=3.0.0 <4.0.0"