Use SO_SNDBUFFORCE instead of SO_SNDBUF

When /proc/sys/net/core/wmem_max is smaller than kMaxMessageSize, we
need to override the limitation.

Bug: 37561460
Test: libappfuse_tests

Change-Id: Ibaac8db61290d661459fdc46f0ae8416f7db1d9e
1 file changed