Revert "DO NOT MERGE Remove focus on PasswordTextView"

This reverts commit 1a96556b.

Reason for revert: Although it makes sense in terms of UX that the PasswordView need not be highlightable, 
this change caused CTS failures, so we decided to revert this change.

Bug:183644428
Test: atest CtsWindowManagerDeviceTestCases:KeyguardLockedTests && 
atest CtsWindowManagerDeviceTestCases:MultiDisplayLockedKeyguardTests

Change-Id: I57f3d671a7c8430dd02cd7ddb9badbaab242f150