gtest_repeat crashes (#7645)

* Moved allocation to avoid crash on gtest_repeat.

Signed-off-by: Mike Balfour <82224783+mbalfour-amzn@users.noreply.github.com>

* Fixed GradientSignal tests to work with gtest_repeat.

Signed-off-by: Mike Balfour <82224783+mbalfour-amzn@users.noreply.github.com>

Code/Framework/AzTest/AzTest/GemTestEnvironment.cpp

@@ -52,7 +52,6 @@ namespace AZ
 
         GemTestEnvironment::GemTestEnvironment()
         {
-            m_parameters = new Parameters;
         }
 
         void GemTestEnvironment::AddDynamicModulePaths(const AZStd::vector<AZStd::string>& dynamicModulePaths)
@@ -84,6 +83,8 @@ namespace AZ
 
             AZ::AllocatorInstance<AZ::SystemAllocator>::Create();
 
+            m_parameters = new Parameters;
+
             AddGemsAndComponents();
             PreCreateApplication();