Reland: Pass apex_info.pb file to delta_generator
target_files contain META/apex_info.pb, which contains metadata about
compressed apexes. Extract this file from target_file.zip, and pass it
to delta_generator. delta_generator will then copy these data to
update_metadata
Test: generate an OTA, make sure a device running an older build can
install the OTA
Bug: 172911822
Change-Id: If0e185a32262a849d533c3316ffdf205cb6628b6
diff --git a/common/utils.h b/common/utils.h
index 616de06..5f6e475 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -144,6 +144,9 @@
// Returns true if |path| exists and is a symbolic link.
bool IsSymlink(const char* path);
+// Return true iff |path| exists and is a regular file
+bool IsRegFile(const char* path);
+
// If |base_filename_template| is neither absolute (starts with "/") nor
// explicitly relative to the current working directory (starts with "./" or
// "../"), then it is prepended the system's temporary directory. On success,