checkapi: allow adding @Deprecated

@JavaPassthrough(annotation="@Deprecated") is now considered as a
compatible change. Checkapi ignores it.

Bug: 174327111
Test: aidl_unittests
Change-Id: I3e43736732929baf63393b3c0bf2bdcaf412e84e
diff --git a/aidl_checkapi.cpp b/aidl_checkapi.cpp
index 9d9387c..d752f44 100644
--- a/aidl_checkapi.cpp
+++ b/aidl_checkapi.cpp
@@ -32,6 +32,7 @@
 
 using android::base::Error;
 using android::base::Result;
+using android::base::StartsWith;
 using std::map;
 using std::set;
 using std::string;
@@ -61,9 +62,15 @@
   };
   vector<string> annotations;
   for (const AidlAnnotation& annotation : node.GetAnnotations()) {
-    if (kIgnoreAnnotations.find(annotation.GetType()) == kIgnoreAnnotations.end()) {
-      annotations.push_back(annotation.ToString());
+    if (kIgnoreAnnotations.find(annotation.GetType()) != kIgnoreAnnotations.end()) {
+      continue;
     }
+    auto annotation_string = annotation.ToString();
+    // adding @Deprecated (with optional args) is okay
+    if (StartsWith(annotation_string, "@JavaPassthrough(annotation=\"@Deprecated")) {
+      continue;
+    }
+    annotations.push_back(annotation_string);
   }
   return annotations;
 }