Clear and re-focus pin password entry field

Under certain conditions, this field can enter an unpredictable state
where it's not focused but the request focus call fails because the
focus flag is set. By clearing the focus before re-requesting, a fully
focused state can be guaranteed.

Bug: 263440452
Test: atest android.appsecurity.cts.DirectBootHostTest#testDirectBootNative
Change-Id: Ib8f0de99abbf99cdbed4c3228c44ee3db105f952