Show help string when onEnrollmentHelp() is called

The help string is not shown when onEnrollmentHelp() is called
between onEnrollmentProgressChange() and mTouchAgainRunnable#run().
To fix this issue, showError() should be called.

Bug: 30274453
Test: manual - start enrolling fingerprint and move finger fast on the sensor

Change-Id: Ie604532940e40cca66dc54b56c3cb4b828a07987
1 file changed