servicemanager: log if doesn't become ctx mgr

Currently, this is a silent failure.

This is made to be fatal in a separate patch, for
revertability.

Bug: 280514080
Test: boot
Change-Id: If5a524f056d77905c818f466c5c677666caa1640
diff --git a/cmds/servicemanager/main.cpp b/cmds/servicemanager/main.cpp
index c1a04dd..520d6f9 100644
--- a/cmds/servicemanager/main.cpp
+++ b/cmds/servicemanager/main.cpp
@@ -131,7 +131,10 @@
     }
 
     IPCThreadState::self()->setTheContextObject(manager);
-    ps->becomeContextManager();
+    if (!ps->becomeContextManager()) {
+        LOG(ERROR) << "Could not become context manager";
+        // TODO(b/280514080): fatal
+    }
 
     sp<Looper> looper = Looper::prepare(false /*allowNonCallbacks*/);