Save task property validation report
Save task property validation report

This also allows skipping the task when no changes are detected in its
inputs.

+review REVIEW-5989

lsmaira/gradle,gradle/gradle,robinverduijn/gradle,blindpirate/gradle,lsmaira/gradle,gstevey/gradle,lsmaira/gradle,robinverduijn/gradle,robinverduijn/gradle,gradle/gradle,lsmaira/gradle,gstevey/gradle,gradle/gradle,lsmaira/gradle,robinverduijn/gradle,lsmaira/gradle,robinverduijn/gradle,gradle/gradle,gradle/gradle,gradle/gradle,robinverduijn/gradle,blindpirate/gradle,robinverduijn/gradle,gstevey/gradle,lsmaira/gradle,blindpirate/gradle,robinverduijn/gradle,lsmaira/gradle,lsmaira/gradle,blindpirate/gradle,gstevey/gradle,gstevey/gradle,gradle/gradle,robinverduijn/gradle,gradle/gradle,blindpirate/gradle,blindpirate/gradle,gstevey/gradle,blindpirate/gradle,robinverduijn/gradle,gradle/gradle,gradle/gradle,blindpirate/gradle,blindpirate/gradle,lsmaira/gradle,blindpirate/gradle,gstevey/gradle,gstevey/gradle,gstevey/gradle,robinverduijn/gradle