Replace usage of Instrumentation#runOnMainSync with ActivityTestRule#runOnUiThread.

ActivityTestRule#runOnUiThread handles exceptions correctly and thus should be used
in place of Instrumentation#runOnMainSync. This changes most of these use-cases
except for tricky cases.

Bug: 31801302
Test: ran support-design:connectedCheck and support-appcompat:connectedCheck
Change-Id: I70904aef89e6bbc2a3cff1b3be697258d666e316
70 files changed