Add ReadonlyArray<string> as an alterative type for $inject.

It may be prudent to make injected dependencies immutable, but we can't Object.freeze() or use the Readonly interfae for our dependency array if $inject only accepts a mutable array of strings.

angular/index.d.ts

@@ -10,7 +10,7 @@ declare var angular: angular.IAngularStatic;
 // Support for painless dependency injection
 declare global {
     interface Function {
-        $inject?: string[];
+        $inject?: string[] | ReadonlyArray<string>;
     }
 }
 
@@ -1205,7 +1205,7 @@ declare namespace angular {
 
         debugInfoEnabled(): boolean;
         debugInfoEnabled(enabled: boolean): ICompileProvider;
-    
+
         /**
          * Sets the number of times $onChanges hooks can trigger new changes before giving up and assuming that the model is unstable.
          * Increasing the TTL could have performance implications, so you should not change it without proper justification.
@@ -1214,7 +1214,7 @@ declare namespace angular {
          */
         onChangesTtl(): number;
         onChangesTtl(limit: number): ICompileProvider;
-    
+
         /**
          * It indicates to the compiler whether or not directives on comments should be compiled.
          * It results in a compilation performance gain since the compiler doesn't have to check comments when looking for directives.
@@ -1223,7 +1223,7 @@ declare namespace angular {
          */
         commentDirectivesEnabled(): boolean;
         commentDirectivesEnabled(enabled: boolean): ICompileProvider;
-    
+
         /**
          * It indicates to the compiler whether or not directives on element classes should be compiled.
          * It results in a compilation performance gain since the compiler doesn't have to check element classes when looking for directives.