[Physical Keyboard] Fix bugs for input keys dialog

set content description on custom radio button and seekbar.
fix typo

Bug: 374229004
Bug: 374229189
Bug: 374229597
Bug: 389973787
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: I3df4b1558c2bad73d9411a0160725d7a35590cc3