Change truststore location in test runner

libcore says java.home is /system, so the truststore path should be
/system/etc/...

This worked on existing android devices because they symlink /etc to
/system/etc. Googletv doesn't symlink, but the test should mimic
reality and look in /system/etc

Confirmed on moto xoom and googletv

Change-Id: I5a7db6842e60ab3aa141d1dc72452ecc47f8fd84
diff --git a/tests/core/runner/src/android/test/InstrumentationCtsTestRunner.java b/tests/core/runner/src/android/test/InstrumentationCtsTestRunner.java
index 5aa2c3b..b2be76a 100644
--- a/tests/core/runner/src/android/test/InstrumentationCtsTestRunner.java
+++ b/tests/core/runner/src/android/test/InstrumentationCtsTestRunner.java
@@ -81,7 +81,7 @@
         System.setProperty("java.io.tmpdir", cacheDir.getAbsolutePath());
         System.setProperty("user.dir", cacheDir.getAbsolutePath());
         System.setProperty("javax.net.ssl.trustStore",
-                "/etc/security/cacerts.bks");
+                "/system/etc/security/cacerts.bks");
 
         TimeZone.setDefault(TimeZone.getTimeZone("GMT"));