Add synchronous transaction to wait for setInputWindow to complete (2/n)

Added InputWindowCommand syncInputWindows

This will allow the client to request SF to wait until setInputWindow
has completed on the InputDispatcher side.

Bug: 123041491
Test: Builds, no execution yet
Change-Id: Ibb5539455d20e4d612696ae7164ce84130bf91b4
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index bf2a03d..8c2538c 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -1083,6 +1083,11 @@
     return *this;
 }
 
+SurfaceComposerClient::Transaction& SurfaceComposerClient::Transaction::syncInputWindows() {
+    mInputWindowCommands.syncInputWindows = true;
+    return *this;
+}
+
 #endif
 
 SurfaceComposerClient::Transaction& SurfaceComposerClient::Transaction::setColorTransform(