Removing string reference to activity context
Removing string reference to activity context

1. Moving current activity to a weak reference

2. Fixing leak issue with shareMangaer

BranchMetrics/Android-Deferred-Deep-Linking-SDK,BranchMetrics/Android-Deferred-Deep-Linking-SDK,BranchMetrics/android-branch-deep-linking,BranchMetrics/android-branch-deep-linking,BranchMetrics/Android-Deferred-Deep-Linking-SDK,BranchMetrics/android-branch-deep-linking,BranchMetrics/android-branch-deep-linking,BranchMetrics/Android-Deferred-Deep-Linking-SDK