Assign bpfloader with CAP_SYS_ADMIN

bpfloader needs to load bpf programs with tracepoints in them. The
tracepoint programs are not activated but are just loaded and pinned.
The kernel expects the process doing this to have CAP_SYS_ADMIN. Since
bpfloader was intended to be a 1-shot run and exit process with security
privileges, lets assign it CAP_SYS_ADMIN so that it is able to load the
tracepoint programs.

Bug: 112334572
Change-Id: Icf9b5d95615e69f5c28dc28f021b07f49710c97d
Signed-off-by: Joel Fernandes <joelaf@google.com>