Core: Cleaning usage of Android classes on core

This got in the code by my mistake on #1209
Merge pull request #1221 from DroidPlanner/coreMinorCleanUp

Core: Cleaning usage of Android classes on core
Android: Removing the unused graph widget.
Android: Removed unused class
Android: Remove unused class
Merge pull request #1222 from DroidPlanner/widgetsCleanUp

Widgets clean up
Revert "UI Action bar cleanup"
Merge pull request #1223 from DroidPlanner/revert-1218-ui_cleanup

Revert "UI Action bar cleanup"
Survey: Added camera information for Sony RX100
Merge pull request #1227 from DroidPlanner/cameraInfo

Survey: Added camera information for Sony RX100
Android: Default the annoying "low signal" warning to not enabled
Merge pull request #1228 from DroidPlanner/lowSignal_warning

Android: Default the annoying "low signal" warning to not enabled