Add protolog-group library

So that we can reference it in Launcher to create the protolog groups
for Launcher.

Test: mp droid
Change-Id: I544be5e2e29d209e19206742df358e5d5c1c1bb8
diff --git a/core/java/Android.bp b/core/java/Android.bp
index 1844215..ab1c9a4 100644
--- a/core/java/Android.bp
+++ b/core/java/Android.bp
@@ -528,6 +528,13 @@
     ],
 }
 
+java_library {
+    name: "protolog-group",
+    srcs: [
+        "com/android/internal/protolog/common/IProtoLogGroup.java",
+    ],
+}
+
 // PackageManager common
 filegroup {
     name: "framework-pm-common-shared-srcs",