fix(ci): join HandlerThreads after quitSafely to eliminate thread restart race

Add join(500) after quitSafely() in MessageManager.destroy() and
KitManagerImpl.reset() so old threads are fully dead before new ones
are created in the next test's startMParticle(). This eliminates the
"Thread starting during runtime shutdown" race on API 28 emulators.

Also revert instrumented-tests.yml timeout_minutes default from 30 to
20 — the hang is in test execution, not emulator boot.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: jamesnrokt

.github/workflows/instrumented-tests.yml

@@ -18,7 +18,7 @@ on:
       timeout_minutes:
         required: false
         type: number
-        default: 30
+        default: 20
 
 permissions:
   contents: read

android-core/src/main/java/com/mparticle/internal/MessageManager.java

@@ -1048,10 +1048,12 @@ public void disable() {
     public static void destroy() {
         if (sMessageHandlerThread != null) {
             sMessageHandlerThread.quitSafely();
+            try { sMessageHandlerThread.join(500); } catch (InterruptedException ignored) { Thread.currentThread().interrupt(); }
             sMessageHandlerThread = null;
         }
         if (sUploadHandlerThread != null) {
             sUploadHandlerThread.quitSafely();
+            try { sUploadHandlerThread.join(500); } catch (InterruptedException ignored) { Thread.currentThread().interrupt(); }
             sUploadHandlerThread = null;
         }
         // Do NOT call startThreads() here — new threads are started lazily when MParticle.start()

android-kit-base/src/main/java/com/mparticle/kits/KitManagerImpl.java

@@ -1336,6 +1336,7 @@ public void onConsentStateUpdated(final ConsentState oldState, final ConsentStat
     public void reset() {
         if (kitHandlerThread != null) {
             kitHandlerThread.quitSafely();
+            try { kitHandlerThread.join(500); } catch (InterruptedException ignored) { Thread.currentThread().interrupt(); }
             kitHandlerThread = null;
             mKitHandler = null;
         }