1. Removes the footer in hearing devices page
2. Moves the footer message to top intro of hearing devices pairing
page
Bug: 321840161
Test: build pass, only simple UI change
Change-Id: I0554f0e6d12f78c1df3efba23792e9c0dc3f061f
Rewrite a new hearing device pairing page with update UI for "See more
devices".
Bug: 307473972
Test: atest HearingDevicePairingFragmentTest
Test: flip the flag com.android.settings.flags.new_hearing_device_pairing_page && atest HearingAidPairingDialogFragmentTest AddDevicePreferenceControllerTest
Change-Id: Ic60601905e3d0d7d7c5b1ef9733652118a211f1d