Fix opacity of expanded shade during transitions

Change-Id: I480e558113cd9f31b7548002265e9b4b78b0ddad
Fixes: 70351996
Fixes: 71443237
Fixes: 73311721
Fixes: 72757727
Test: packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/ScrimControllerTest.java
Test: unlock with fp. pattern
Test: pull down shade adjust brightness on bouncer and launcher
Test: unlock with fingerprint from pulsing notification