Allow parsing boot image with header version 3
The boot image header version no longer contains a page_size field;
and it assumes the block size is always 4096. Also, the order of the
header fields are different in version 3 from the previous versions.
While the position of "header_version" is fixed at position #9 across
all image headers.
This cl handles header version 3 separately from the previous versions.
Also create a stub implementation since the parsing of boot image is only
used in android.
Test: unit tests, generate incremental OTA for the affected package, build with stub file
5 files changed