SDK / exoplayer

Note that it's not possible for the library to enforce that
the flag is adhered to, since it's possible for applications
to inject custom implementations of DataSource (there's no
requirement they even extend HttpDataSource for network
requesting implementations). It's possible for applications
to replace pretty much anything in the library, so there's
no other place we could put the flag where we could make
this guarantee. Hence this is a best-effort that will work
when using HttpDataSource implementations that we provide.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=136500947