Fix incremental aapt builds

If a resource was moved / removed without any other timestamp updates,
ninja would not re-run aapt. To fix this, add a list of resource files
into the same command as aapt (echo ... >/dev/null). That way if the
list changes, ninja will recognize the command line changing and rerun
aapt.

Bug: 67315436
Test: mmma cts/tests/autofillservice
Test: mv cts/tests/autofillservice/res/layout/welcome_activity.xml \
      cts/tests/autofillservice/res/layout/welcome_activity_test.xml
Test: mmma cts/tests/autofillservice

Change-Id: Ia93ac4ff48910fed74a1f1539ce4e1f5a9db023f