Fixing broken tests on 2 and 3 button devices.

Bug: 143488140
Change-Id: I30886da129825b800984baa08742ac4dfcf4a599
diff --git a/quickstep/tests/src/com/android/quickstep/FallbackRecentsTest.java b/quickstep/tests/src/com/android/quickstep/FallbackRecentsTest.java
index ffe55b6..bd8ab08 100644
--- a/quickstep/tests/src/com/android/quickstep/FallbackRecentsTest.java
+++ b/quickstep/tests/src/com/android/quickstep/FallbackRecentsTest.java
@@ -121,7 +121,8 @@
                     UiDevice.getInstance(getInstrumentation()).executeShellCommand(
                             getLauncherCommand(getLauncherInMyProcess()));
                     // b/143488140
-                    mLauncher.pressHome();
+                    mDevice.pressHome();
+                    mDevice.waitForIdle();
                 }
             }
         };