Android: enable WebRTC HW H264 with a flag by default

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 486a2df49249c438e1e56e27dae6b4e8706ac3d9..3bfb99cf81e118ed1fdd506202017269457d0323 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -92284,6 +92284,7 @@ value.
   <int value="-1467332609" label="tab-management-experiment-type-anise"/>
   <int value="-1460462432" label="disable-media-source"/>
   <int value="-1456004000" label="VrShell:disabled"/>
+  <int value="-1449344919" label="AndroidWebRtcHWH264Encoding:disabled"/>
   <int value="-1443796945" label="OfflinePagesSharing:disabled"/>
   <int value="-1440152291" label="disable-gesture-typing"/>
   <int value="-1438279809" label="GamepadExtensions:disabled"/>
@@ -92892,6 +92893,7 @@ value.
   <int value="1460958818" label="NTPForeignSessionsSuggestions:enabled"/>
   <int value="1465624446" label="disable-zero-copy"/>
   <int value="1466380480" label="enable-device-discovery-notifications"/>
+  <int value="1469255213" label="AndroidWebRtcHWH264Encoding:enabled"/>
   <int value="1469407485" label="disable-accelerated-2d-canvas"/>
   <int value="1479248574" label="disable-voice-input"/>
   <int value="1481562816" label="disable-password-link"/>