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
disabled calibration when the drone is in a flying state.
Editor: Allow negative altitude mission planning
Merge pull request #1230 from ne0fhyk/fix_issue_1229

Disabled calibration when the drone is in a flying state.
Merge pull request #1231 from DroidPlanner/negativeAltitudes

Editor: Allow negative altitude mission planning
added analytics collection for the type of mission items used.ˆˆ
added analytics measurement for the use of the editor multi edit button.
added analytics to measure the user's response to the preference dialogs.
Merge pull request #1233 from ne0fhyk/analytics_update

Analytics update