GPII-161: Add support for some specific GNOME solutions

This patch includes the support to deal with these following gsettings
schemas:

  - org.gnome.shell.overrides
  - org.gnome.desktop.wm.preferences
GPII-75: added support for save functionality through the flow manager.
GPII-259: Including org.freedesktop.xrandr on the solution registry
GPII-259: Adding org.freedesktop.xrandr into installedSolution.json
GPII-259: Adding 'randy' N&P set for test purposes
GPII-277: Using the new Android's native settings Settings Handler

[changes]
  * Adding the new Settings Handler to be used into Talkback's solution
entry
  * Improving paulina N&P set to to change the speech rate of the active
TTS engine
GPII-343: Using the new Settings Handler for ALSA volume

[changes]
  * Adding ALSA into the solutions registry
  * Adding ALSA into installedSolutions.json
  * Adding an example N&P set (alsa.json)
Merge branch 'master' into GPII-75
Merge branch 'master' into GPII-75
GPII-308: Adding transformation for system volume common term

It matches with "-provisional-general.-provisional-volume" common term.
GPII-75: updated tests to work with kettle test utils. Added development tests for global dev config.
GPII-75: added tests for user save via the flow manager.
GPII-75: updated flow manager save tests.
GPII-269: updated prefs server API to return {token: '...', preferences: [...]}
GPII-217: added CORS support to prefs server.
GPII-217: simplified CORS config for pref server.
GPII-75: added io flow manager grade, tests for save.
Merge remote-tracking branch 'upstream/master' into GPII-277
GPII-397: Solution entry for Android's Configuration API settingsHandler

* Adding a new solution entry
* Including the new solution into the deviceReporter
* Adding maguro.json N&P example set
GPII-398: Using the new Android's audio manager settings handler

* Adding com.android.audioManager into the deviceReporter
* Adding a solution registry entry for the new solution
* Adding an N&P set (audio) for testing purposes