Add a warning for FRenderableManager (#8210)

In some cases, users set materials first without providing render primitives, which has incurred the attribute mismatching warning. This isn't helpful because users don't know what action they should take to remove the warning.

Emit the warning only when the primitive handle is initialized so the AttributeBitset is properly populated.

BUGS=[372755205]

filament/src/components/RenderableManager.cpp

@@ -807,7 +807,10 @@ void FRenderableManager::setMaterialInstanceAt(Instance instance, uint8_t level,
             primitives[primitiveIndex].setMaterialInstance(mi);
             AttributeBitset const required = material->getRequiredAttributes();
             AttributeBitset const declared = primitives[primitiveIndex].getEnabledAttributes();
-            if (UTILS_UNLIKELY((declared & required) != required)) {
+            // Print the warning only when the handle is available. Otherwise this may end up
+            // emitting many invalid warnings as the `declared` bitset is not populated yet.
+            bool const isPrimitiveInitialized = !!primitives[primitiveIndex].getHwHandle();
+            if (UTILS_UNLIKELY(isPrimitiveInitialized && (declared & required) != required)) {
                 slog.w << "[instance=" << instance.asValue() << ", primitive @ " << primitiveIndex
                        << "] missing required attributes ("
                        << required << "), declared=" << declared << io::endl;