[Physical Keyboard] Move Dialog to DialogFragment

Move Bounce key and Slow key Dialog to DialogFragment, dialog will not
be dismissed when screen rotate.

Bug: 390243451
Bug: 374037603
Flag: com.android.settings.keyboard.keyboard_and_touchpad_a11y_new_page_enabled
Test: atest
packages/apps/Settings/tests/robotests/src/com/android/settings/inputmethod/

Change-Id: Ide87dbf8214f411941114281e7a5e8c81f75bdd4