Workaround for b/36228253

Dynamic shortcuts must have target activities, but somehow the invariant
was broken.

Bug: 36228253

Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest1 -w com.android.frameworks.servicestests
Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest2 -w com.android.frameworks.servicestests
Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest3 -w com.android.frameworks.servicestests
Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest4 -w com.android.frameworks.servicestests
Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest5 -w com.android.frameworks.servicestests
Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest6 -w com.android.frameworks.servicestests
Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest7 -w com.android.frameworks.servicestests
Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest8 -w com.android.frameworks.servicestests
Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest9 -w com.android.frameworks.servicestests
Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest10 -w com.android.frameworks.servicestests
Change-Id: I9163d57121f102d88baa3e34791877412719da50