Replace DataType enum with type & add runtime dataTypes (elastic#82231)

## Summary

Expands on pattern added in elastic#82188

Replace `enum DataType` with TS type `DataType` & runtime JS `dataTypes`
```diff
- export enum DataType {
-  logs = 'logs',
-  metrics = 'metrics',
-}
+ export const dataTypes = {
+  Logs: 'logs',
+  Metrics: 'metrics',
+ } as const;
+ export type DataType = typeof dataTypes;
```

<img width="513" alt="Screen Shot 2020-11-02 at 5 13 56 PM" src="https://user-images.githubusercontent.com/57655/97926339-f5898c00-1d30-11eb-8935-92aad936aeea.png">
<img width="774" alt="Screen Shot 2020-11-02 at 5 14 05 PM" src="https://user-images.githubusercontent.com/57655/97926341-f5898c00-1d30-11eb-8d68-b39e2904cf85.png">
<img width="780" alt="Screen Shot 2020-11-02 at 5 19 50 PM" src="https://user-images.githubusercontent.com/57655/97926342-f5898c00-1d30-11eb-9799-95d77bfc1757.png">

# Conflicts:
#	x-pack/plugins/ingest_manager/common/constants/epm.ts
#	x-pack/plugins/ingest_manager/common/types/models/epm.ts

x-pack/plugins/ingest_manager/common/constants/epm.ts

@@ -8,3 +8,13 @@ export const PACKAGES_SAVED_OBJECT_TYPE = 'epm-packages';
 export const INDEX_PATTERN_SAVED_OBJECT_TYPE = 'index-pattern';
 export const INDEX_PATTERN_PLACEHOLDER_SUFFIX = '-index_pattern_placeholder';
 export const MAX_TIME_COMPLETE_INSTALL = 60000;
+
+export const requiredPackages = {
+  System: 'system',
+  Endpoint: 'endpoint',
+} as const;
+
+export const dataTypes = {
+  Logs: 'logs',
+  Metrics: 'metrics',
+} as const;

x-pack/plugins/ingest_manager/common/types/models/epm.ts

@@ -7,6 +7,7 @@
 // Follow pattern from https://github.com/elastic/kibana/pull/52447
 // TODO: Update when https://github.com/elastic/kibana/issues/53021 is closed
 import { SavedObject, SavedObjectAttributes, SavedObjectReference } from 'src/core/public';
+import { dataTypes, requiredPackages } from '../../constants';
 
 export enum InstallationStatus {
   installed = 'installed',
@@ -44,10 +45,7 @@ export enum ElasticsearchAssetType {
   transform = 'transform',
 }
 
-export enum DataType {
-  logs = 'logs',
-  metrics = 'metrics',
-}
+export type DataType = typeof dataTypes;
 
 export enum AgentAssetType {
   input = 'input',

x-pack/plugins/ingest_manager/server/services/epm/kibana/index_pattern/install.ts

@@ -12,6 +12,8 @@ import {
 import * as Registry from '../../registry';
 import { loadFieldsFromYaml, Fields, Field } from '../../fields/field';
 import { getPackageKeysByStatus } from '../../packages/get';
+import { dataTypes } from '../../../../../common/constants';
+import { ValueOf } from '../../../../../common/types';
 import {
   InstallationStatus,
   RegistryPackage,
@@ -119,7 +121,7 @@ export async function installIndexPatterns(
   const packageVersionsInfo = await Promise.all(packageVersionsFetchInfoPromise);
 
   // for each index pattern type, create an index pattern
-  const indexPatternTypes = [DataType.logs, DataType.metrics];
+  const indexPatternTypes = Object.values(dataTypes);
   indexPatternTypes.forEach(async (indexPatternType) => {
     // if this is an update because a package is being uninstalled (no pkgkey argument passed) and no other packages are installed, remove the index pattern
     if (!pkgName && installedPackages.length === 0) {
@@ -146,7 +148,7 @@ export async function installIndexPatterns(
 // of all fields from all data streams matching data stream type
 export const getAllDataStreamFieldsByType = async (
   packages: RegistryPackage[],
-  dataStreamType: DataType
+  dataStreamType: ValueOf<DataType>
 ): Promise<Fields> => {
   const dataStreamsPromises = packages.reduce<Array<Promise<Field[]>>>((acc, pkg) => {
     if (pkg.data_streams) {
@@ -391,7 +393,7 @@ export const ensureDefaultIndices = async (callCluster: CallESAsCurrentUser) =>
   // that no matching indices exist https://github.com/elastic/kibana/issues/62343
   const logger = appContextService.getLogger();
   return Promise.all(
-    Object.keys(DataType).map(async (indexPattern) => {
+    Object.values(dataTypes).map(async (indexPattern) => {
       const defaultIndexPatternName = indexPattern + INDEX_PATTERN_PLACEHOLDER_SUFFIX;
       const indexExists = await callCluster('indices.exists', { index: defaultIndexPatternName });
       if (!indexExists) {

x-pack/plugins/ingest_manager/server/types/index.tsx

@@ -74,6 +74,7 @@ export {
   PostAgentEnrollRequest,
   PostAgentCheckinRequest,
   DataType,
+  dataTypes,
 } from '../../common';
 
 export type CallESAsCurrentUser = LegacyScopedClusterClient['callAsCurrentUser'];