Remove useless TestRunner for KeyStoreTests

InstrumentationTestRunner can enumerate the test cases to run without a
special TestRunner in KeyStoreTests.

Change-Id: I9e849d035d78b51ca9a73c52012dab448fc4a7ee
diff --git a/testrunner/test_defs.xml b/testrunner/test_defs.xml
index ada90d2..35aea0f 100644
--- a/testrunner/test_defs.xml
+++ b/testrunner/test_defs.xml
@@ -94,7 +94,6 @@
 <test name="keystore-unit"
     build_path="frameworks/base/keystore/tests"
     package="android.security.tests"
-    runner=".KeyStoreTestRunner"
     coverage_target="framework"
     continuous="true" />