Adding waiting for Launcher initialization

This may fix or ease TIS sometimes not receiving events.

Bug: 154157191
Change-Id: I5db9e88397788014dbba9716d777a2b97347828c

tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java

@@ -297,6 +297,7 @@ public abstract class AbstractLauncherUiTest {
             clearPackageData(mDevice.getLauncherPackageName());
             mLauncher.enableDebugTracing();
             mLauncherPid = mLauncher.getPid();
+            mLauncher.waitForLauncherInitialized();
         }
     }
 

tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java

@@ -625,6 +625,7 @@ public final class LauncherInstrumentation {
         mInstrumentation.getUiAutomation().setOnAccessibilityEventListener(
                 e -> Log.d("b/155926212", e.toString()));
         try (LauncherInstrumentation.Closable e = eventsCheck()) {
+            waitForLauncherInitialized();
             // Click home, then wait for any accessibility event, then wait until accessibility
             // events stop.
             // We need waiting for any accessibility event generated after pressing Home because