Fix blaming exempted apps

Applications which are exempted from 'screen ON', are already blamed
when the app is in foreground and Wi-Fi is connected. For any screen
state change, the blame state for the exempted application should not
be changed.

Bug: 284823118
Test: atest com.android.server.wifi.WifiLockManagerTest
Change-Id: Ifad51a4bfeffacabda93c9c0282f6ceb38ba4299
2 files changed