Reset all Jest mocks in NetworkController tests (#19295)

This makes it possible to test that mock functions are called the
correct amount of times (otherwise Jest will think that a mock function
has been called for as many tests as exist in the NetworkController unit
test suite).

app/scripts/controllers/network/network-controller.test.ts

@@ -153,6 +153,7 @@ describe('NetworkController', () => {
     nock.enableNetConnect('localhost');
     nock.cleanAll();
     resetAllWhenMocks();
+    jest.resetAllMocks();
   });
 
   describe('constructor', () => {