Preview alignment improvements

[KryptKode]

Notes

• improve preview alignments
• centre the PreviewView between the top action icons and the bottom mode switcher view for 4:3, 3:2 (video mode - SD) and 1:1 resolutions, when not full screen
• fix NullPointerException thrown in the GestureDetector listeneronFling. The reason why it happens even though we added the null checks and caught exception is this:

The GestureDetector.SimpleOnGestureListener class is in Java and the MotionEvent parameters to onFling are marked as @NonNull. When used in a Kotlin file, the compiler will add Instrisincs.checkNotNullParameter checks before our code and this is what causes the crash

To fix it, we have to create GestureDetectorListener, a Java wrapper file for the SimpleOnGestureListener class and mark the parameters as @Nullable. So now, the Kotlin compiler will not add these non-null checks.

[tibbi]

placement works well, hope the crashfix will work too. Thanks