Add support for 4GB memory option

The 4GB memory option was not added everywhere.

Fixes firebase#834

Author: Leon Radley

src/cloud-functions.ts

@@ -507,6 +507,7 @@ export function optionsToTrigger(options: DeploymentOptions) {
       '512MB': 512,
       '1GB': 1024,
       '2GB': 2048,
+      '4GB': 4096,
     };
     trigger.availableMemoryMb = _.get(memoryLookup, options.memory);
   }

src/function-builder.ts

@@ -144,7 +144,7 @@ export function region(
  * Configure runtime options for the function.
  * @param runtimeOptions Object with optional fields:
  * 1. `memory`: amount of memory to allocate to the function, possible values
- *    are: '128MB', '256MB', '512MB', '1GB', and '2GB'.
+ *    are: '128MB', '256MB', '512MB', '1GB', '2GB', and '4GB'.
  * 2. `timeoutSeconds`: timeout for the function in seconds, possible values are
  *    0 to 540.
  * 3. `failurePolicy`: failure policy of the function, with boolean `true` being
@@ -188,7 +188,7 @@ export class FunctionBuilder {
    * Configure runtime options for the function.
    * @param runtimeOptions Object with optional fields:
    * 1. `memory`: amount of memory to allocate to the function, possible values
-   *    are: '128MB', '256MB', '512MB', '1GB', and '2GB'.
+   *    are: '128MB', '256MB', '512MB', '1GB', '2GB', and '4GB'.
    * 2. `timeoutSeconds`: timeout for the function in seconds, possible values are
    *    0 to 540.
    * 3. `failurePolicy`: failure policy of the function, with boolean `true` being