Don't depend on nonexistent manifest when manifest_check is disabled.

This is a follow-up for https://android-review.googlesource.com/1614807.

Bug: 132357300
Test: lunch aosp_cf_x86_64_phone-userdebug && m
Test: lunch qemu_trusty_arm64-userdebug && \
  m out/soong/.intermediates/packages/apps/DocumentsUI/DocumentsUI/android_common/DocumentsUI-unsigned.apk
Change-Id: I84c5d171bd976f35f342abd94b592506c71e4b1d