Pinner service for pinning files into memory

Pin key files into memory to prevent having to fetch from flash
after boot.  Improves system performance by preventing page cache
thrash.  Retrieves files from a device-specific overlay to allow
specialization.

bug 28251566

Change-Id: I8532f52bd70271794dd7576976d13a524849ce7b

services/java/com/android/server/SystemServer.java

@@ -643,6 +643,10 @@ public final class SystemServer {
             traceBeginAndSlog("ConnectivityMetricsLoggerService");
             mSystemServiceManager.startService(MetricsLoggerService.class);
             Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
+
+            traceBeginAndSlog("PinnerService");
+            mSystemServiceManager.startService(PinnerService.class);
+            Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
         } catch (RuntimeException e) {
             Slog.e("System", "******************************************");
             Slog.e("System", "************ Failure starting core service", e);