Set BITCODE_GENERATION_MODE to 'bitcode' - Both Release and Debug were being built with -fembed-bitcode-marker   which doesn't actually embed bitcode. - Now -fembed-bitcode is passed which should embed the bitcode correctly.
Set BITCODE_GENERATION_MODE to 'bitcode'
- Both Release and Debug were being built with -fembed-bitcode-marker
  which doesn't actually embed bitcode.
- Now -fembed-bitcode is passed which should embed the bitcode correctly.

Should fix https://github.com/google/google-api-objectivec-client-for-rest/issues/171

WilliamDenniss/AppAuth-iOS,openid/AppAuth-iOS,WilliamDenniss/AppAuth-iOS,openid/AppAuth-iOS,WilliamDenniss/AppAuth-iOS,openid/AppAuth-iOS