Revert^2 "Rename DexJar interface method to DexJarBuildPath."

This reverts commit b0dc851ff4eca650042b52ce4ff06cb7e0312b77.

Reason for revert: relanding original change. Build failures were
  caused by a race with another CL: https://r.android.com/1320920

Test: lunch aosp_cf_x86_phone-userdebug && m
Change-Id: Ic9016582dae7773b4d4f84a63425f1ef7a5d061f
diff --git a/java/aar.go b/java/aar.go
index c8daf83..7413c80 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -730,7 +730,7 @@
 	return android.Paths{a.classpathFile}
 }
 
-func (a *AARImport) DexJar() android.Path {
+func (a *AARImport) DexJarBuildPath() android.Path {
 	return nil
 }