chore(tsickle): add @Annotation annotations

This lets users continue using runtime-sideeffect Decorators if they choose,
only down-leveling the marked ones to Annotations.

Also remove the "skipTemplateCodegen" option, which is no longer needed
since Angular compiles with tsc-wrapped rather than ngc. The former doesn't
include any codegen.

modules/@angular/http/tsconfig-es2015.json

@@ -1,12 +1,8 @@
 {
-  "angularCompilerOptions": {
-    "skipTemplateCodegen": true
-  },
   "compilerOptions": {
     "baseUrl": ".",
     "declaration": true,
     "stripInternal": true,
-    "emitDecoratorMetadata": true,
     "experimentalDecorators": true,
     "module": "es2015",
     "moduleResolution": "node",

modules/@angular/http/tsconfig-es5.json

@@ -1,12 +1,8 @@
 {
-  "angularCompilerOptions": {
-    "skipTemplateCodegen": true
-  },
   "compilerOptions": {
     "baseUrl": ".",
     "declaration": true,
     "stripInternal": true,
-    "emitDecoratorMetadata": true,
     "experimentalDecorators": true,
     "module": "commonjs",
     "moduleResolution": "node",