Fix exception checking after native prepare call

Test: atest MediaPlayerUnitTest
Bug: 279575542
Change-Id: I33da791e4eabfc350b6e135795c067678e730752
diff --git a/media/jni/android_media_MediaPlayer.cpp b/media/jni/android_media_MediaPlayer.cpp
index 9552200..44aff64 100644
--- a/media/jni/android_media_MediaPlayer.cpp
+++ b/media/jni/android_media_MediaPlayer.cpp
@@ -385,6 +385,10 @@
 
     process_media_player_call( env, thiz, mp->prepare(), "java/io/IOException", "Prepare failed." );
 
+    if (env->ExceptionCheck()) {
+        return UNKNOWN_ERROR;
+    }
+
     // update the piid
     Parcel *request = parcelForJavaObject(env, piidParcel);
     auto reply = std::make_unique<Parcel>();
@@ -407,6 +411,10 @@
 
     process_media_player_call( env, thiz, mp->prepareAsync(), "java/io/IOException", "Prepare Async failed." );
 
+    if (env->ExceptionCheck()) {
+        return UNKNOWN_ERROR;
+    }
+
     // update the piid
     Parcel *request = parcelForJavaObject(env, piidParcel);
     auto reply = std::make_unique<Parcel>();