RESTRICT AUTOMERGE ValidateMediaProfiles searches multiple directories

The file "media_profiles_V1_0.xml" may reside in /product/etc, /odm/etc,
/vendor/etc or /system/etc. The current test code assumes the file lives
in /vendor/etc. This change makes the test search through the four
directories.

Test: atest VtsValidateMediaProfiles

Bug: 159576670
Change-Id: Icb763631192ca591768aa371bc31b4c722a75366