Rename DexJar interface method to DexJarBuildPath.

This is a prerequisite change before adding DexJarInstallPath.

Test: lunch aosp_cf_phone-userdebug && m
Change-Id: I033e08b8bb06c0a844a6bbbfcdc48ce33e9c95cf
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index ed61d4b..9d93838 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -255,7 +255,7 @@
 		return -1, nil
 	}
 
-	jar, hasJar := module.(interface{ DexJar() android.Path })
+	jar, hasJar := module.(interface{ DexJarBuildPath() android.Path })
 	if !hasJar {
 		return -1, nil
 	}
@@ -296,7 +296,7 @@
 		panic("unknown boot image: " + image.name)
 	}
 
-	return index, jar.DexJar()
+	return index, jar.DexJarBuildPath()
 }
 
 // buildBootImage takes a bootImageConfig, creates rules to build it, and returns the image.