adb: kill adb_thread_{create, join, detach, exit}.

We have std::thread now, so we can delete this cruft.

Test: python test_device.py
Test: adb_test
Test: wine adb_test.exe
Test: /data/nativetest/adbd_test/adbd_test
Change-Id: Ie1c1792547b20dec45e2a62ce6515fcb981c3ef8
diff --git a/adb/shell_service.cpp b/adb/shell_service.cpp
index d4f334b..ee821f8 100644
--- a/adb/shell_service.cpp
+++ b/adb/shell_service.cpp
@@ -90,6 +90,7 @@
 
 #include <memory>
 #include <string>
+#include <thread>
 #include <unordered_map>
 #include <vector>
 
@@ -392,12 +393,7 @@
 
 bool Subprocess::StartThread(std::unique_ptr<Subprocess> subprocess, std::string* error) {
     Subprocess* raw = subprocess.release();
-    if (!adb_thread_create(ThreadHandler, raw)) {
-        *error =
-            android::base::StringPrintf("failed to create subprocess thread: %s", strerror(errno));
-        kill(raw->pid_, SIGKILL);
-        return false;
-    }
+    std::thread(ThreadHandler, raw).detach();
 
     return true;
 }