Allow assistant app to access any shortcuts

Bug: 68760723
Test: adb shell am instrument -w -e class com.android.server.pm.ShortcutManagerTest1 -w com.android.frameworks.servicestests
Test: adb shell am instrument -w -e class com.android.server.pm.ShortcutManagerTest2 -w com.android.frameworks.servicestests
Test: adb shell am instrument -w -e class com.android.server.pm.ShortcutManagerTest3 -w com.android.frameworks.servicestests
Test: adb shell am instrument -w -e class com.android.server.pm.ShortcutManagerTest4 -w com.android.frameworks.servicestests
Test: adb shell am instrument -w -e class com.android.server.pm.ShortcutManagerTest5 -w com.android.frameworks.servicestests
Test: adb shell am instrument -w -e class com.android.server.pm.ShortcutManagerTest6 -w com.android.frameworks.servicestests
Test: adb shell am instrument -w -e class com.android.server.pm.ShortcutManagerTest7 -w com.android.frameworks.servicestests
Test: adb shell am instrument -w -e class com.android.server.pm.ShortcutManagerTest8 -w com.android.frameworks.servicestests
Test: adb shell am instrument -w -e class com.android.server.pm.ShortcutManagerTest9 -w com.android.frameworks.servicestests
Test: adb shell am instrument -w -e class com.android.server.pm.ShortcutManagerTest10 -w com.android.frameworks.servicestests
Test: cts-tradefed run cts-dev --skip-device-info --skip-preconditions --skip-system-status-check com.android.compatibility.common.tradefed.targetprep.NetworkConnectivityChecker -a armeabi-v7a -l INFO -m CtsShortcutManagerTestCases
Change-Id: I8c0f0ba1f01c1da7df44bb235abdaa94c36d86d3