Amend OpenGL/ES Conformance Submission Package Requirements

The current practice is that all bugfixes should be merged
into the CTS repo before being used in a submission.
This change promotes this practices to a requirement.

Components: OpenGL

Change-Id: Id5e5782c0418cbedb0ca23b0abd06051021b63ec
diff --git a/external/openglcts/README.md b/external/openglcts/README.md
index f14ef55..36647ab 100644
--- a/external/openglcts/README.md
+++ b/external/openglcts/README.md
@@ -396,14 +396,20 @@
 and produce stable results. It is, therefore, important to ensure that a port to a
 new platform can support surfaces that fulfill width and height requirements.
 
-### Other Allowable Porting Changes
+### Other Allowable Changes
 
-Other than changes needed for porting, the only changes that are permitted are
-changes to fix bugs in the conformance test. A bug in the conformance test is
-a behavior which causes clearly incorrect execution (e.g., hanging, crashing,
+Changes to fix bugs in the conformance test are allowed. A bug in the conformance
+test is a behavior which causes clearly incorrect execution (e.g., hanging, crashing,
 or memory corruption), OR which requires behavior which contradicts or exceeds
-the requirements of the relevant OpenGL or OpenGL ES Specification. Changes
-required to address either of these issues typically require [waivers](#waivers).
+the requirements of the relevant OpenGL or OpenGL ES Specification. Before
+being used for a submission, bugfixes must be accepted and merged into
+the CTS repository. `git cherry-pick` is strongly recommended as a method of
+applying bug fixes.
+
+Other changes must be accompanied by a [waiver](#waivers).
+
+NOTE: When cherry-picking patches on top of release tag, please use `git cherry-pick -x`
+to include original commit hash in the commit message.
 
 Running the Tests
 ------------------------