health HAL uses "default" service name

The getService() and registerAsService() methods of interface objects
now have default parameters of "default" for the service name. HALs
will not have to use any service name unless they want to register
more than one service.

Test: builds

Bug: 33844934
Change-Id: I5cfe9ae6c6e386fe04d48db7a88538f8ad82aae9
diff --git a/health/1.0/default/HealthService.cpp b/health/1.0/default/HealthService.cpp
index 107f33d..55848d2 100644
--- a/health/1.0/default/HealthService.cpp
+++ b/health/1.0/default/HealthService.cpp
@@ -23,5 +23,5 @@
 using android::hardware::defaultPassthroughServiceImplementation;
 
 int main() {
-    return defaultPassthroughServiceImplementation<IHealth>("health");
+    return defaultPassthroughServiceImplementation<IHealth>();
 }