Increase minSdk to 24.

Manually set to M
 - MissedCallNotifierTest (not sure what the issue is here...)
 - CallLogGroupBuilderTest (because a check was removed, some NPEs are thrown)
 - MainSearchControllerTest (/system/etc/fonts.xml (No such file or directory))

Ignore Tests
 - a few random ones in incallui/answer/impl/hint (shared prefs aren't working for some reason)
 - VisualVoicemailUpdateTaskTest (disabled the whole test, issue unclear)

Bug: 73902692
Test: tap
PiperOrigin-RevId: 190030202
Change-Id: I1e9b61d758a61582c5a183ee884dd2181d1c10de