Add statsd protos to platform_protos rule

BUG: 167962588
TEST: TH
TEST: Local build [ m com.android.os.statsd ]
Merged-In: I053f2a211ea28c2f181937af3d58ad16b235d096
Change-Id: I637a1af27d572924e88b1f8a930fc45d0794fa20