Always clear password reset token when removing device owner

Move the token removal logic inside clearDeviceOwnerLocked so
it's executed by all paths where DO is removed. This also fixes
a bug where mLockPatternUtils.removeEscrowToken is throwing
exception due to it's not inside a clear binder identity block.

Bug: 280093211
Test: DeviceOwnerTest#clearDeviceOwnerApp_escrowTokenExists_success
Change-Id: Ifaa1ffbd0f29b62fd05a9d746c26b44c52f4eaa0