Launcher3: Exclude overview lens activity from recents

With lens activity starting as a new task, avoid showing Google
app in the recents tasks list.

Change-Id: Ib903292c64b854dcb38117d02edf5013f2855ac1

quickstep/src/com/android/quickstep/util/ImageActionUtils.java

@@ -178,6 +178,7 @@ public static void startLensActivity(Context context, Supplier<Bitmap> bitmapSup
                     .setComponent(
                             new ComponentName(Utilities.GSA_PACKAGE, Utilities.LENS_SHARE_ACTIVITY))
                     .addFlags(FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK)
+                    .addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS)
                     .addFlags(FLAG_GRANT_READ_URI_PERMISSION)
                     .setType("image/png")
                     .putExtra(Intent.EXTRA_STREAM, uri)