5/n: Add support for initial coex cases

1) Adds a way to enable/disable this. By default, this is disabled on
   top of tree (so this change should be a no-op. By default, tests
   enable the advanced behavior.
2) Adds a dump to "adb shell dumpsys biometric"

Bug: 193089985
Test: atest CoexCoordinatorTest
Test: atest com.android.server.biometrics
Test: adb shell dumpsys biometric (with and without secure setting)

Change-Id: I9fe553e9d4b78e34a20b9130f854143a355275bc