Tentative fix for initializer list thread race condition

Tentative fix for this Duo report [here](https://2dimensions.slack.com/archives/C029X99PETE/p1692977259716259)
Make sure we initialize & start the thread so every other field is already initialized.

[Source](https://en.cppreference.com/w/cpp/language/constructor)
```
Initialization order

The order of member initializers in the list is irrelevant: the actual order of initialization is as follows:
1) If the constructor is for the most-derived class, virtual bases are initialized in the order in which they appear in depth-first left-to-right traversal of the base class declarations (left-to-right refers to the appearance in base-specifier lists).
2) Then, direct bases are initialized in left-to-right order as they appear in this class's base-specifier list.
3) Then, non-static data member are initialized in order of declaration in the class definition.
4) Finally, the body of the constructor is executed.
```

Also, a sort-of repro [here](https://alexanderhoughton.co.uk/blog/stdmutex-crash-on-initial-lock-interesting-thread-releated-bug-with-fix-included/)

Diffs=
4ff3d9cee Tentative fix for initializer list thread race condition (#5920)

Co-authored-by: Umberto Sonnino <[email protected]>

.rive_head

@@ -1 +1 @@
-d35df04272e659d8244c776e9c4f558452888501
+4ff3d9cee0a9a9acd7874ab6782015f7c11a661e

app/src/androidTest/java/app/rive/runtime/example/RiveActivityLifecycleTest.kt

@@ -37,7 +37,7 @@ class RiveActivityLifecycleTest {
         // Close it down.
         activityScenario.close()
         // Background thread deallocates asynchronously.
-        waitUntil(500.milliseconds) { controller.refCount == 0 }
+        waitUntil(1500.milliseconds) { controller.refCount == 0 }
         assertFalse(controller.isActive)
         assertNull(controller.file)
         assertNull(controller.activeArtboard)
@@ -79,7 +79,7 @@ class RiveActivityLifecycleTest {
         // Close it down.
         activityScenario.close()
         // Background thread deallocates asynchronously.
-        waitUntil(500.milliseconds) { controller.refCount == 0 }
+        waitUntil(1500.milliseconds) { controller.refCount == 0 }
         assertFalse(controller.isActive)
         assertNull(controller.file)
         assertNull(controller.activeArtboard)

kotlin/src/main/cpp/clean_all.sh

@@ -40,7 +40,9 @@ popd
 
 # PLS
 pushd "$RIVE_RUNTIME_DIR"/../pls/out
-make clean
+if [[ -e Makefile ]]; then
+  make clean
+fi
 rm -rf ./android
 rm -rf ./dependencies
 rm -rf ./obj

kotlin/src/main/cpp/include/helpers/worker_thread.hpp

@@ -36,11 +36,11 @@ class WorkerThread
     using WorkID = uint64_t;
 
     WorkerThread(const char* name, Affinity affinity, const RendererType rendererType) :
-        m_RendererType(rendererType),
-        mName(name),
-        mAffinity(affinity),
-        mThread(std::thread([this]() { threadMain(); }))
-    {}
+        m_RendererType(rendererType), mName(name), mAffinity(affinity), mWorkMutex{}
+    {
+        // Don't launch the worker thread until all of our objects are fully initialized.
+        mThread = std::thread([this]() { threadMain(); });
+    }
 
     ~WorkerThread() { terminateThread(); }
 
@@ -139,15 +139,16 @@ class WorkerThread
 
     const std::string mName;
     const Affinity mAffinity;
-    std::thread mThread;
 
     WorkID m_lastPushedWorkID = 0;
     std::atomic<WorkID> m_lastCompletedWorkID = 0;
     bool mIsTerminated = false;
 
-    std::mutex mWorkMutex;
     std::queue<std::function<void(EGLThreadState*)>> mWorkQueue;
     std::condition_variable_any m_workPushedCondition;
     std::condition_variable_any m_workedCompletedCondition;
+
+    std::mutex mWorkMutex;
+    std::thread mThread;
 };
 } // namespace rive_android