Release: version 1.15.2.2
Merge remote-tracking branch 'upstream/master'

Conflicts:
	mopub-sdk/src/main/java/com/mopub/mobileads/BaseHtmlWebView.java
	mopub-sdk/src/main/java/com/mopub/mobileads/BaseWebView.java

Updated to version 1.15.2.2