binderRpcBenchmark: test many proxy behavior

Run benchmark. Here are the results on cuttlefish, sorted by type:

--------------------------------------------------------------------
Benchmark                          Time             CPU   Iterations
--------------------------------------------------------------------
BM_collectProxies/0/10       1533424 ns       730683 ns          754 kernel
BM_collectProxies/0/100     11205890 ns      5137458 ns          100 kernel
BM_collectProxies/0/1000   142801788 ns     62453023 ns           13 kernel
BM_collectProxies/0/5000  1027138576 ns    343139318 ns            2 kernel
BM_collectProxies/0/10000 2693937199 ns    649060571 ns            1 kernel
BM_collectProxies/0/20000 6821069171 ns    993179895 ns            1 kernel

BM_collectProxies/1/10       1548213 ns       777264 ns          703 rpc
BM_collectProxies/1/100     11427798 ns      5646163 ns          100 rpc
BM_collectProxies/1/1000   139841963 ns     64293601 ns           10 rpc
BM_collectProxies/1/5000   704893121 ns    289427753 ns            2 rpc
BM_collectProxies/1/10000 2248307827 ns    646102929 ns            1 rpc
BM_collectProxies/1/20000 5540550470 ns   1045339220 ns            1 rpc

BM_collectProxies/2/10       1992236 ns      1131694 ns          641 rpc_tls
BM_collectProxies/2/100     17621061 ns      9583246 ns           73 rpc_tls
BM_collectProxies/2/1000   170796751 ns     93129790 ns           10 rpc_tls
BM_collectProxies/2/5000  1062981321 ns    473419293 ns            2 rpc_tls
BM_collectProxies/2/10000 2146783259 ns    782427997 ns            1 rpc_tls
BM_collectProxies/2/20000 7441237493 ns   2041843159 ns            1 rpc_tls

Note - super-linear scaling of behavior above 1000 binder objects.

Because we see this scaling in both RPC binder and kernel binder (but to
a lesser extend in 'rpc' - ignore 'rpc_tls' which has a lot of extra
overhead), this indicates that part of the nonlinearity likely comes
from userspace code OR RPC-binder itself has non-linearity similar
to the binder driver.

Fixes: 298049518
Test: binderRpcBenchmark

Change-Id: Ib43ac68a1b1f9c11df06af59e3c5572abeabbd5d