Add new module type for adb_keys.

Bug: 371107666
Change-Id: Ibaee842f807bc829ca615d5754851e03a4aa5548
Test: CIs
diff --git a/etc/Android.bp b/etc/Android.bp
index 580c54f..8e043b8 100644
--- a/etc/Android.bp
+++ b/etc/Android.bp
@@ -11,6 +11,7 @@
         "soong-android",
     ],
     srcs: [
+        "adb_keys.go",
         "install_symlink.go",
         "otacerts_zip.go",
         "prebuilt_etc.go",