MergeJavaResources fix introduces artificial skipWhenEmpty

[ghale]

The MergeJavaResources fix creates a new input that is marked with skipWhenEmpty(true). This is normally not a problem, but in situations where the inputs are empty, this will cause the task to be skipped with a NO-SOURCE outcome rather than creating an empty jar. This causes problems for downstream tasks that expect the jar to exist, even if it is empty.

[ghale]

This issue can affect MergeNativeLibsTask as well. In cases where this task is not merging native libraries that are part of the build or compiled renderscript or anything like that (i.e. it is only merging external dependencies), the "sources" of the task will appear empty and the task will be skipped without merging the libraries. This is also fixed with ab23543 which is in version 1.0.1 and above.