Enable building WebRTCDemo apk using Release webrtc libs, take 2.
Enable building WebRTCDemo apk using Release webrtc libs, take 2.

Now passing BUILDTYPE=Release to both the make that builds the libs and the
ndk-build that builds the app makes the app use non-Debug libs.

Review URL: https://webrtc-codereview.appspot.com/966029

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: be5b5ba49087aae1cfcb095893207f9fa41c1089

sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc