Add ANDROID_PARTNER_CUSTOMIZATION_PHENOTYPE to CachedFeatureFlags

This flag needs caching, because AppHooks#getCustomizationProvider() is
often called before native is initialized. See also crbug.com/1069609

Bug: 1069609
Change-Id: I5113ed8277f55290db37476955ce87ed2eba72b8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2146056Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: Ender <ender@google.com>
Commit-Queue: bttk <bttk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759005}

chrome/android/java/src/org/chromium/chrome/browser/ChromeCachedFlags.java

@@ -45,6 +45,7 @@ public class ChromeCachedFlags {
 
         // clang-format off
         List<String> featuresToCache = Arrays.asList(
+                ChromeFeatureList.ANDROID_PARTNER_CUSTOMIZATION_PHENOTYPE,
                 ChromeFeatureList.COMMAND_LINE_ON_NON_ROOTED,
                 ChromeFeatureList.CHROME_DUET,
                 ChromeFeatureList.CHROME_DUET_ADAPTIVE,

chrome/browser/flags/android/java/src/org/chromium/chrome/browser/flags/CachedFeatureFlags.java

@@ -47,6 +47,7 @@ public class CachedFeatureFlags {
      */
     private static Map<String, Boolean> sDefaults = new HashMap<String, Boolean>() {
         {
+            put(ChromeFeatureList.ANDROID_PARTNER_CUSTOMIZATION_PHENOTYPE, false);
             put(ChromeFeatureList.HOMEPAGE_LOCATION_POLICY, false);
             put(ChromeFeatureList.SERVICE_MANAGER_FOR_DOWNLOAD, false);
             put(ChromeFeatureList.SERVICE_MANAGER_FOR_BACKGROUND_PREFETCH, false);