Allow passing custom headers for requests

[acoutts]

Same deal from bazrafkan/google_place#27

Required to use platform-specific API keys where you must provide the following headers:

    final headers = <String, String>{
      if (defaultTargetPlatform == TargetPlatform.iOS)
        'x-ios-bundle-identifier': Env().bundleIdentifier, // com.my.app
      if (defaultTargetPlatform == TargetPlatform.android) ...{
        'x-android-package': Env().bundleIdentifier, // com.my.app
        'x-android-cert': Env().ANDROID_SIGNING_KEY_SHA1, // signing key used to build/publish the app
      }
    };

[acoutts]

@bazrafkan any chance to review this please? Thanks.

[acoutts]

Hello is there any update?

[acoutts]

Hello is there any chance for this to be merged?

[acoutts]

@bazrafkan

[acoutts]

Hello?

[acoutts]

Bumping again

[acoutts]

bump

[acoutts]

Hello?