Reset module registry flag when resetting React Instance

Summary:
D12911108 fixed a UBN race condition by adding a flag for module registry.

This flag was never reset if react instance gets reset, causing an assert to fire in IG.

Reviewed By: fkgozali

Differential Revision: D13010651

fbshipit-source-id: e20453f3c546d759a58fd7fb93553f774410905f

React/CxxBridge/RCTCxxBridge.mm

@@ -880,6 +880,7 @@ struct RCTInstanceCallback : public InstanceCallback {
 
   _loading = NO;
   _valid = NO;
+  _moduleRegistryCreated = NO;
 
   dispatch_async(dispatch_get_main_queue(), ^{
     if (self->_jsMessageThread) {
@@ -976,6 +977,7 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithBundleURL:(__unused NSURL *)bundleUR
   _loading = NO;
   _valid = NO;
   _didInvalidate = YES;
+  _moduleRegistryCreated = NO;
 
   if ([RCTBridge currentBridge] == self) {
     [RCTBridge setCurrentBridge:nil];