Add external/golang-protobuf

Bug: 64081790
diff --git a/default.xml b/default.xml
index 3065947..ea22df3 100644
--- a/default.xml
+++ b/default.xml
@@ -144,6 +144,7 @@
   <project path="external/gemmlowp" name="platform/external/gemmlowp" groups="pdk" />
   <project path="external/giflib" name="platform/external/giflib" groups="pdk,qcom_msm8x26" />
   <project path="external/glide" name="platform/external/glide" groups="pdk" />
+  <project path="external/golang-protobuf" name="platform/external/golang-protobuf" groups="pdk" />
   <project path="external/google-benchmark" name="platform/external/google-benchmark" groups="pdk" />
   <project path="external/google-breakpad" name="platform/external/google-breakpad" groups="dragon,pdk-fs" />
   <project path="external/google-fonts/carrois-gothic-sc" name="platform/external/google-fonts/carrois-gothic-sc" groups="pdk" />