Install data_libs using relative_install_path property

Test: Added to data_libs tests
Test: Manually verified with bionic-unit-tests
Test: Treehugger
Change-Id: I28a8e08e3409f1e7c7bb72f4351310b57f35f513

cc/cc.go

@@ -1401,9 +1401,9 @@ func (c *Module) IsTestPerSrcAllTestsVariation() bool {
 	return ok && test.isAllTestsVariation()
 }
 
-func (c *Module) DataPaths() android.Paths {
+func (c *Module) DataPaths() []android.DataPath {
 	if p, ok := c.installer.(interface {
-		dataPaths() android.Paths
+		dataPaths() []android.DataPath
 	}); ok {
 		return p.dataPaths()
 	}