Merge pull request #2134 from VinRudramurthy/release-6.6.3.a1

Folders: If there is only 1 folder/collection is available, made invisible reorder container.
not logging parent eventId in collection end
event issue has been resolved.
Added previous button to the Flag information popup.
Merge branch 'release-6.6.3.a1' of https://github.com/Gooru/Gooru-Web into release-6.6.3.a1
Merge pull request #2137 from mitraj/release-6.6.3.a1

Added previous button to the Flag information popup.
Merge pull request #2136 from shivalinga/release-6.6.3.a1

not logging parent eventId in collection end event issue has been resolved.
Folders: Added comments at missing places.
Merge branch 'release-6.6.3.a1' of https://github.com/Gooru/Gooru-Web into release-6.6.3.a1