Do not crash if setSystemFont is called twice.

ActivityThread.mBoundApplication has @UnsupportedAppUsage, so apps can
re-send BIND_APPLICATION message with the same AppBindData by using
reflection.

Bug: 174969232
Test: manually tested with the test app in the bug
Change-Id: Ic96d670f6346d9d1373607b4ae6e78b78194a09c
1 file changed