When I initialize AdMob even without ads I got 1,5 seconds of delay (app freeze).
This is where the delay come from:
MobileAds.initialize(getApplicationContext(), "ca-app-pub-123");
Also when I initialize I got this error in my Log:
W/ResourcesManager: Asset path '/system/framework/com.android.media.remotedisplay.jar' does not exist or contains no resources.
W/ResourcesManager: Asset path '/system/framework/com.android.location.provider.jar' does not exist or contains no resources.
W/art: Long monitor contention event with owner method=java.lang.Class dalvik.system.DexFile.defineClassNative(java.lang.String, java.lang.ClassLoader, long) from DexFile.java:4294967294 waiters=0 for 388ms
W/art: Long monitor contention event with owner method=java.lang.Class dalvik.system.DexFile.defineClassNative(java.lang.String, java.lang.ClassLoader, long) from DexFile.java:4294967294 waiters=1 for 389ms