Adjust NOT_SHIPPED labels of some README.chromium's

Commit c11f4b9a ("Mark a few build-time-only third-party
README.chromiums as NOT_SHIPPED") switched the "License" field of some
projects used only at build-time to "NOT_SHIPPED". However,
expects NOT_SHIPPED to be set in "License File", which means those
projects were still being listed in about:credits.

Revert the changes to the "License" field done in that commit and switch
"License Files" to NOT_SHIPPED instead. This applies to:
- third_party/ijar
- third_party/jmake
- third_party/markdown (in addition, set "License" to "3 BSD-Clause" to
  better reflect its nature and to match the Android whitelist in
- third_party/ocmock

third_party/class-dump was removed in 17ca744 ("Remove old iossim
code (pre-Xcode 8) and class-dump") and third_party/proguard was
adjusted in 1116f0d ("retrace.jar checked in").,,,

Cr-Commit-Position: refs/heads/master@{#428377}
GitOrigin-RevId: 71fdc05bd32d94dc5a63845a612fecc33bd8a15f
1 file changed