Some documentation updates.
Merge from Widevine repo of http://go/wvgerrit/50941
bug: 79940606 OEMCrypto_PST_Report are network byte order
bug: 79874942 [Documentation] PST_Report struct layout differs from documentation
bug: 74010869 CGMS Best Effort
test: documentation change only
Change-Id: I1e9149efcfa5d91c503b74e6776ebb8f25cda15c
Merge from Widevine repo of http://go/wvgerrit/41641
test: In child CL.
bug: 64001862 OEMCrypto V14 for Android P
Change-Id: I707c4dc24aa534c92b099cd310b9afd09168d456