v6.0.0-alpha.5

Feature:

• [Android/IOS] Add CSAI using google IMA (need to be enable in gradle for android)
• [Android] add new events on tracks changed

Bugfix:

• [IOS] avoid controls to be displayed when disabled
• [IOS] ensure audio and subtitle tracks are well reported
• [IOS] improve logs
• [IOS] Fix crash in presentFullScreenPlayer
• [ìOS] Fix crash when changing source rapidly
• [Android/IOS] sample improvement
• [Android] fix progress report which doesn't respect configured timing
• [Android] Fix crash due to null activity
• [DOC] various improvements