RPC Server never returns

In normal operation AVmPayload_runVsockRpcServer should never return -
the calling thread joins the server's thread pool, and we provide no
way to shut down the server. If the server does exit, that indicates a
failure somewhere.

If there is a failure of any sort (including unexepected server exit)
there is nothing the caller can do, so we panic rather than returning
a bool.

Update callers to not expect a return value.

I got slightly carried away and also:
- Modified compsvc to use AVmPayload_runVsockRpcServer rather than
  rolling its own.
- Turned on unsafe_op_in_unsafe_fn in the API implementation. That
  requires us to explicitly mark unsafe blocks in unsafe functions, so
  I've gone through and done that. I checked that all the top-level
  functions that should be marked unsafe are.

Bug: 243512108
Test: atest MicrodroidTests
Test: composd_cmd test-compile
Change-Id: I447ce0baa09d6a244ffe2ba7ab08092be3cd0f82
diff --git a/tests/testapk/src/native/testbinary.cpp b/tests/testapk/src/native/testbinary.cpp
index 5c217ff..c0a8c0e 100644
--- a/tests/testapk/src/native/testbinary.cpp
+++ b/tests/testapk/src/native/testbinary.cpp
@@ -119,10 +119,8 @@
     auto testService = ndk::SharedRefBase::make<TestService>();
 
     auto callback = []([[maybe_unused]] void* param) { AVmPayload_notifyPayloadReady(); };
-    if (!AVmPayload_runVsockRpcServer(testService->asBinder().get(), testService->SERVICE_PORT,
-                                      callback, nullptr)) {
-        return Error() << "RPC Server failed to run";
-    }
+    AVmPayload_runVsockRpcServer(testService->asBinder().get(), testService->SERVICE_PORT, callback,
+                                 nullptr);
 
     return {};
 }