Revert "Added android.software.device_admin feature."

This reverts commit e157812629b6e48a6c1620322fcbd62605780fef.

Bug: 189246976
Bug: 178412797
Test: adb shell pm list features | grep device_admin || echo NOT_FOUND

Change-Id: I68083666a37ef1d349d6be864939c9817443acc2
diff --git a/data/etc/car_core_hardware.xml b/data/etc/car_core_hardware.xml
index adfd6e2..cc0ee82 100644
--- a/data/etc/car_core_hardware.xml
+++ b/data/etc/car_core_hardware.xml
@@ -47,12 +47,6 @@
     <feature name="android.software.secure_lock_screen" />
     <feature name="android.software.input_methods" />
 
-
-    <!-- Feature to support device admins -->
-    <!-- TODO(b/178412797): not fully supported yet, CTS tests are still
-         failing. -->
-    <feature name="android.software.device_admin" />
-
     <!-- devices with GPS must include android.hardware.location.gps.xml -->
     <!-- devices with an autofocus camera and/or flash must include either
          android.hardware.camera.autofocus.xml or