idmap2: Set aidl_return to true on success

idmap2d did not set the aidl return value to true when
IdmapHeader::IsUpToDate succeeded. This regressed OMS initialization
time.

This change sets aidl_return to true when the header is up-to-date and
also replaces usages of `uint32_t` for fulfilled_policies with
`PolicyBitmask`.

Bug: 158491243
Bug: 158535227
Bug: 158468195
Test: enable/disable overlays and onserve that verify succeeds
Test: change the values of enforce overlayable and fulfilled policies
      and confirm that idmap verify fails
Change-Id: If8febbfd0283d53211263690f85e2970706a33b7
diff --git a/cmds/idmap2/idmap2d/Idmap2Service.cpp b/cmds/idmap2/idmap2d/Idmap2Service.cpp
index 908d966..f95b73f 100644
--- a/cmds/idmap2/idmap2d/Idmap2Service.cpp
+++ b/cmds/idmap2/idmap2d/Idmap2Service.cpp
@@ -70,12 +70,12 @@
 }
 
 Status GetCrc(const std::string& apk_path, uint32_t* out_crc) {
-  const auto overlay_zip = ZipFile::Open(apk_path);
-  if (!overlay_zip) {
+  const auto zip = ZipFile::Open(apk_path);
+  if (!zip) {
     return error(StringPrintf("failed to open apk %s", apk_path.c_str()));
   }
 
-  const auto crc = GetPackageCrc(*overlay_zip);
+  const auto crc = GetPackageCrc(*zip);
   if (!crc) {
     return error(crc.GetErrorMessage());
   }
@@ -121,6 +121,7 @@
                                   bool* _aidl_return) {
   SYSTRACE << "Idmap2Service::verifyIdmap " << overlay_apk_path;
   assert(_aidl_return);
+
   const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_apk_path);
   std::ifstream fin(idmap_path);
   const std::unique_ptr<const IdmapHeader> header = IdmapHeader::FromBinaryStream(fin);
@@ -156,13 +157,10 @@
 
   auto up_to_date =
       header->IsUpToDate(target_apk_path.c_str(), overlay_apk_path.c_str(), target_crc, overlay_crc,
-                         fulfilled_policies, enforce_overlayable);
-  if (!up_to_date) {
-    *_aidl_return = false;
-    return error(up_to_date.GetErrorMessage());
-  }
+                         ConvertAidlArgToPolicyBitmask(fulfilled_policies), enforce_overlayable);
 
-  return ok();
+  *_aidl_return = static_cast<bool>(up_to_date);
+  return *_aidl_return ? ok() : error(up_to_date.GetErrorMessage());
 }
 
 Status Idmap2Service::createIdmap(const std::string& target_apk_path,