[ADI][35/N] Remove "set-developer-verification-policy" shell command

Shell can no longer change the developer verification policy. Tests have been migrated off from using this command. Removing it now.

Test: builds
BUG: 360129657
FLAG: android.content.pm.verification_service
Change-Id: Ie1f439f032eb3f420e17a3914f1bee0d48b39561