Fix FrameworksServicesTests:StorageManagerServiceTest

Use androidx.test not android.support.test.
And remove android.support.test from build by removing unnecessary
frameworks-base-testutils > android.support.test dependency

Bug: 117990406
Test: m checkbuild; atest FrameworksServicesTests:StorageManagerServiceTest
Change-Id: Ia825e0926b46855f9056739441cb21a065692076
diff --git a/tests/utils/testutils/Android.bp b/tests/utils/testutils/Android.bp
index 4be6534..0a9e964 100644
--- a/tests/utils/testutils/Android.bp
+++ b/tests/utils/testutils/Android.bp
@@ -19,7 +19,7 @@
 
     srcs: ["java/**/*.java"],
 
-    static_libs: ["android-support-test"],
+    static_libs: ["junit"],
 
     libs: [
         "android.test.runner",