Flip proprietary codecs to false for Android chromium builds.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index e8042fea050ca0797c35939cf401baf0b2a6604e..4b2f2dacdfd4f1ced1ac2ad7d4dfe79329c3b7ce 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -833,10 +833,9 @@
           'use_browser_spellchecker%': 1,
         }],
 
-        # Android OS includes support for proprietary codecs regardless of
-        # building Chromium or Google Chrome. We also ship Google Chrome and
-        # Chromecast with proprietary codecs.
-        ['OS=="android" or branding=="Chrome" or chromecast==1', {
+        # Enables proprietary codecs and demuxers; e.g. H264, MOV, AAC, and MP3.
+        # We always build Google Chrome and Chromecast with proprietary codecs.
+        ['branding=="Chrome" or chromecast==1', {
           'proprietary_codecs%': 1,
         }, {
           'proprietary_codecs%': 0,