* Add config properties to specify snapshot blob file names.
This adds the ability of the shell to override the default
dart aot snapshot blob file names, and it wires up Android's
FlutterMain to recognize the properties in the app's manifest.
This will be used for flutter applications that build their
binary snapshots into files other than the default ones
that the engine uses.
This patch should contain all the code we need to run Flutter on
Fuchsia's software framebuffer (without text). I haven't actually tried
running the code, so I'm sure it doesn't work yet.
Also, rename SkyViewClient to RuntimeDelegate. These names are more
sensible.
This patch also cleans up the RuntimeDelegate a bit, for example by
removing support for flushing real-time events, which aren't used.
