Revert of [Android] Re-enable content_browsertests on main waterfall. (https://codereview.chromium.org/132403005/)

Reason for revert:
content_browsertests have been crashy and flaky since being re-enabled.

Looks like they crashing on shutdown, but I'm not sure.

Failed:
http://build.chromium.org/p/chromium.linux/builders/Android%20Tests/builds/11552
http://build.chromium.org/p/chromium.linux/builders/Android%20Tests/builds/11554

On this one, content_browsertests crashed but still passed. This caused INJECT_EVENTS exceptions in later tests.
http://build.chromium.org/p/chromium.linux/builders/Android%20Tests%20%28dbg%29/builds/18163

We see the same thing downstream.


Original issue's description:
> [Android] Re-enable content_browsertests on main waterfall.
> 
> There's enough infra capacity now.
> 
> BUG=
> R=navabi@chromium.org, navabi@google.com
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=247341

TBR=navabi@chromium.org,navabi@google.com,frankf@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/135363005

git-svn-id: http://src.chromium.org/svn/trunk/src/build@247547 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/pylib/gtest/gtest_config.py

@@ -6,6 +6,7 @@
 
 # Add new suites here before upgrading them to the stable list below.
 EXPERIMENTAL_TEST_SUITES = [
+    'content_browsertests',
     'content_gl_tests',
 ]
 
@@ -31,7 +32,6 @@ STABLE_TEST_SUITES = [
     'webkit_unit_tests',
     'breakpad_unittests',
     'sandbox_linux_unittests',
-    'content_browsertests',
 ]
 
 WEBRTC_CHROMIUM_TEST_SUITES = [