Revert "Pass apex_info.pb file to delta_generator"

This reverts commit 4e5da3e9d7459e3d983db943ebf3cb4c36af9c60.

Reason for revert:  b/178908708

Change-Id: I616da64ffda5b94044f3493861d6d01aebfaad61
diff --git a/update_metadata.proto b/update_metadata.proto
index a1f093c..5e86f8f 100644
--- a/update_metadata.proto
+++ b/update_metadata.proto
@@ -359,16 +359,10 @@
 // Definition has been duplicated from
 // $ANDROID_BUILD_TOP/build/tools/releasetools/ota_metadata.proto. Keep in sync.
 message ApexInfo {
-  optional string package_name = 1;
-  optional int64 version = 2;
-  optional bool is_compressed = 3;
-  optional int64 decompressed_size = 4;
-}
-
-// Definition has been duplicated from
-// $ANDROID_BUILD_TOP/build/tools/releasetools/ota_metadata.proto. Keep in sync.
-message ApexMetadata {
-  repeated ApexInfo apex_info = 1;
+  required string package_name = 1;
+  required int64 version = 2;
+  required bool is_compressed = 3;
+  required int64 decompressed_size = 4;
 }
 
 message DeltaArchiveManifest {