Missing PendingIntent mutability flag

Missing PendingIntent mutability flag

Apps targeting Android 12 and higher must specify either FLAG_IMMUTABLE or FLAG_MUTABLE when constructing a PendingIntent.

FLAG_IMMUTABLE is available since target SDK 23, and is almost always the best choice. See https://developer.android.com/guide/components/intents-filters#CreateImmutablePendingIntents for a list of common exceptions to this rule.

Issue id: UnspecifiedImmutableFlag

https://developer.android.com/about/versions/12/behavior-changes-12#pending-intent-mutability

https://goo.gle/UnspecifiedImmutableFlag