An internal customer is seeing flickering on some high FPS phones.
While we try and reproduce / gain more knowledge of this problem this PR adds a AndroidManifest.xml flag to disable their usage.
The boolean flag is:
```
"io.flutter.embedding.android.DisableImageReaderPlatformViews"
```
Adding the following to your manifest will disable their usage:
```
<meta-data
android:name="io.flutter.embedding.android.DisableImageReaderPlatformViews"
android:value="true" />
```
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