Set path property for filegroup modules

The path property specifies the base directory for Java files. This can
be used by the build system to filter (or filter-out) Java files by
their package names.

Bug: 135922046
Test: m
Change-Id: I390373a5f40216a7b49f121997960e028d1b8823
diff --git a/android_icu4j/Android.bp b/android_icu4j/Android.bp
index 195749f..29ebd8b 100644
--- a/android_icu4j/Android.bp
+++ b/android_icu4j/Android.bp
@@ -31,6 +31,7 @@
         "//libcore/mmodules/intracoreapi",
     ],
     srcs: ["src/main/java/**/*.java"],
+    path: "src/main/java",
 }
 
 // Rule generating resource lib for android_icu4j.