Update comments for kUnsupportedClassLoaderContextEncoding. (partially cherry picked from commit 60bf7f88d43ea1b2694732df8a59e6ff43bc816b) Bug: 249984283 Test: N/A Change-Id: I55c344f3f178e9749b3a0b8c169c1da49d2a3c37 Merged-In: I23f651f013672defb2e61af0a744ff6e6d128bfb