APIs to watch active op changes

System singed components can watch for starting/finishing of
long running app ops. Also protected the APIs to watch op mode
changes with a singature permission for the cross-uid use case.

Test: atest com.android.server.appops.AppOpsActiveWatcherTest

bug:64085448

Change-Id: Id7fe79ce1de4c5690b4f52786424ec5a5d9eb0fa
diff --git a/Android.bp b/Android.bp
index e65ba0f..ea1ed91 100644
--- a/Android.bp
+++ b/Android.bp
@@ -356,6 +356,7 @@
         "core/java/android/speech/IRecognitionService.aidl",
         "core/java/android/speech/tts/ITextToSpeechCallback.aidl",
         "core/java/android/speech/tts/ITextToSpeechService.aidl",
+        "core/java/com/android/internal/app/IAppOpsActiveCallback.aidl",
         "core/java/com/android/internal/app/IAppOpsCallback.aidl",
         "core/java/com/android/internal/app/IAppOpsService.aidl",
         "core/java/com/android/internal/app/IBatteryStats.aidl",