rename services-stub-sources filegroup to services-all-sources

The filegroup contains all source files for the system server. Calling
it services-stub-sources is misleading and is causing a confusion with
'services-stubs.sources' which is the metalava-filtered source files for
the stub library 'services-stub'.

Bug: N/A
Test: m
Change-Id: I123fbee3c5b5f4d3e8e070e4374d40effc6b799c

services/Android.bp

@@ -6,7 +6,7 @@ filegroup {
 }
 
 filegroup {
-    name: "services-stub-sources",
+    name: "services-all-sources",
     srcs: [
         ":services.core-sources",
         ":services.accessibility-sources",
@@ -111,7 +111,7 @@ filegroup {
 
 droidstubs {
     name: "services-stubs.sources",
-    srcs: [":services-stub-sources"],
+    srcs: [":services-all-sources"],
     installable: false,
     // TODO: remove the --hide options below
     args: " --show-annotation android.annotation.SystemApi\\(client=android.annotation.SystemApi.Client.MODULE_LIBRARIES,process=android.annotation.SystemApi.Process.SYSTEM_SERVER\\)" +