[memprof] Make the raw binary format the default.

Set the default memprof serialization format as binary. 9 tests are
updated to use print_text=true. Also fixed an issue with concatenation
of default and test specified options (missing separator).

Differential Revision: https://reviews.llvm.org/D113617

GitOrigin-RevId: aacaebc6c22f81b13598aac69dee4b076f669e3e
14 files changed