bpfloader.rc: set /proc/sys/kernel/unprivileged_bpf_disabled to 0

Needed to not have to carry
  https://android-review.googlesource.com/c/kernel/common/+/1886896
for 5.16-rc1+ kernels

We set this before the bpfloader even executes so it will always be
ready before anyone has a chance to use it.

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I418a534d6550c5b57286e261e6988d2debdf237f

bpfloader/bpfloader.rc

@@ -15,6 +15,9 @@
 # considered to have booted successfully.
 #
 on load_bpf_programs
+    # Linux 5.16-rc1 has changed the default to 2 (disabled but changeable),
+    # but we need 0
+    write /proc/sys/kernel/unprivileged_bpf_disabled 0
     # Enable the eBPF JIT -- but do note that on 64-bit kernels it is likely
     # already force enabled by the kernel config option BPF_JIT_ALWAYS_ON
     write /proc/sys/net/core/bpf_jit_enable 1