Drop dependency of android.test.mock -> android.test.base.

There should be no such dependency.

Test: lunch aosp_cf_x86_phone-userdebug && m
Bug: 169137403
Bug: 132357300
Change-Id: Iaa7414be66581c01c6acbf367dc165cd8af78615

data/etc/platform.xml

@@ -227,8 +227,7 @@
     <library name="android.test.base"
             file="/system/framework/android.test.base.jar" />
     <library name="android.test.mock"
-            file="/system/framework/android.test.mock.jar"
-            dependency="android.test.base" />
+            file="/system/framework/android.test.mock.jar" />
     <library name="android.test.runner"
             file="/system/framework/android.test.runner.jar"
             dependency="android.test.base:android.test.mock" />