Update work challenge to align with material next

Re-land I6cca39d447e37310c287d1a0eb0468565e9fcd37 after it was reverted
due to CTS failure. The original commit made changes to existing styles
where are shared by other layouts hence causing issues. Fix by creating
new styles instead. Also explicitly set the orientation in the password
view's RelativeLayout, which isn't needed according to documentation but
helps fixing the UI layout issue for some reason.

Update the briefcase icon to be solid fill.

Bug: 191948779
Test: android.server.biometrics.BiometricActivityTests
Change-Id: I185ac28aff4478a4d251c2e5145e5f360131d274