Profile and reduce mobile network consumption

[cmcewen]

There's a few optimization on the mobile app that we want to explore to reduce bandwidth.

• Profile data usage
• While profiling the app I noticed some of the test scenarios aren't complete so I started filling them in (in progress)
• Turning the light client on and off easily - had some issues with crashes
• Stopping syncing headers when not on WiFI/4G
• Don't require restarting the app to enable data saver mode
• Understand non-blockchain traffic (blockchain-api, firebase, etc)