Allow users to switch between manual and autoscale for fixed collections (#299)

- removed the `isFixed` check in both new and old settings tab so that the options to switch between manual and autoscale shows up for fixed collections
- updated the message below the text box to inform the users that the max RU for fixed collections is 10000
- updated validation rule so that the max RU cannot exceed 10000 for fixed collections for both autoscale and manual

src/Explorer/Controls/Settings/SettingsUtils.tsx

@@ -131,13 +131,12 @@ export const parseConflictResolutionProcedure = (procedureFromBackEnd: string):
 };
 
 export const getSanitizedInputValue = (newValueString: string, max: number): number => {
-  let newValue = parseInt(newValueString);
+  const newValue = parseInt(newValueString);
   if (isNaN(newValue)) {
-    newValue = zeroValue;
-  } else if (newValue > max) {
-    newValue = Math.floor(newValue / 10);
+    return zeroValue;
   }
-  return newValue;
+  // make sure new value does not exceed the maximum throughput
+  return Math.min(newValue, max);
 };
 
 export const isDirty = (current: isDirtyTypes, baseline: isDirtyTypes): boolean => {