microdroid: each partition in payload has size in it

When creating the composite disk image for payload, add fillers with size of
the backing files so that microdroid can read block devices easily with its
original size.

filler with size makes each partition well aligned with 4k boundary and the
last 4byte conveys the size(BE).

Bug: 187783952
Test: MicrodroidHostTestCases
Change-Id: I072873779df4737448112e262fc1b051c0229ea8
1 file changed
tree: 3db123d5eb0d16fbc6804815ee58a96ab5e5ac61
  1. apex/
  2. authfs/
  3. compos/
  4. docs/
  5. microdroid/
  6. tests/
  7. virtmanager/
  8. vm/
  9. zipfuse/
  10. .clang-format
  11. PREUPLOAD.cfg