Add system_ext deps to check-vintf-all

The GSIs provide some framework HALs through system_ext so
check-vintf-all needs to depend on them in order to have them available
when checking with vitffm.

Test: lunch aosp_arm64-trunk_staging-userdebug && m check-vintf-all
Bug: 266741352
Change-Id: Id3eaad3a839c72a25aa8921a93de82bb119b0d8f