Un-hide string set persistence methods in Preference

6 years is enough time for API approval.

Bug 27324328

Change-Id: I5d5af0fc291250cd9ea5b50cd5031378475eacec
diff --git a/api/current.txt b/api/current.txt
index b027912..c564fa3 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -29525,6 +29525,7 @@
     method protected int getPersistedInt(int);
     method protected long getPersistedLong(long);
     method protected java.lang.String getPersistedString(java.lang.String);
+    method public java.util.Set<java.lang.String> getPersistedStringSet(java.util.Set<java.lang.String>);
     method public android.preference.PreferenceManager getPreferenceManager();
     method public android.content.SharedPreferences getSharedPreferences();
     method public boolean getShouldDisableView();
@@ -29559,6 +29560,7 @@
     method protected boolean persistInt(int);
     method protected boolean persistLong(long);
     method protected boolean persistString(java.lang.String);
+    method public boolean persistStringSet(java.util.Set<java.lang.String>);
     method public void restoreHierarchyState(android.os.Bundle);
     method public void saveHierarchyState(android.os.Bundle);
     method public void setDefaultValue(java.lang.Object);
diff --git a/api/system-current.txt b/api/system-current.txt
index 25b0cc2..b4cd6a5 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -31895,6 +31895,7 @@
     method protected int getPersistedInt(int);
     method protected long getPersistedLong(long);
     method protected java.lang.String getPersistedString(java.lang.String);
+    method public java.util.Set<java.lang.String> getPersistedStringSet(java.util.Set<java.lang.String>);
     method public android.preference.PreferenceManager getPreferenceManager();
     method public android.content.SharedPreferences getSharedPreferences();
     method public boolean getShouldDisableView();
@@ -31929,6 +31930,7 @@
     method protected boolean persistInt(int);
     method protected boolean persistLong(long);
     method protected boolean persistString(java.lang.String);
+    method public boolean persistStringSet(java.util.Set<java.lang.String>);
     method public void restoreHierarchyState(android.os.Bundle);
     method public void saveHierarchyState(android.os.Bundle);
     method public void setDefaultValue(java.lang.Object);
diff --git a/api/test-current.txt b/api/test-current.txt
index a8a9f4c..b8caf6b 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -29535,6 +29535,7 @@
     method protected int getPersistedInt(int);
     method protected long getPersistedLong(long);
     method protected java.lang.String getPersistedString(java.lang.String);
+    method public java.util.Set<java.lang.String> getPersistedStringSet(java.util.Set<java.lang.String>);
     method public android.preference.PreferenceManager getPreferenceManager();
     method public android.content.SharedPreferences getSharedPreferences();
     method public boolean getShouldDisableView();
@@ -29569,6 +29570,7 @@
     method protected boolean persistInt(int);
     method protected boolean persistLong(long);
     method protected boolean persistString(java.lang.String);
+    method public boolean persistStringSet(java.util.Set<java.lang.String>);
     method public void restoreHierarchyState(android.os.Bundle);
     method public void saveHierarchyState(android.os.Bundle);
     method public void setDefaultValue(java.lang.Object);
diff --git a/core/java/android/preference/Preference.java b/core/java/android/preference/Preference.java
index 5d64af5..d41bc07 100644
--- a/core/java/android/preference/Preference.java
+++ b/core/java/android/preference/Preference.java
@@ -1494,11 +1494,9 @@
      * @return True if the Preference is persistent. (This is not whether the
      *         value was persisted, since we may not necessarily commit if there
      *         will be a batch commit later.)
-     * @see #getPersistedString(Set)
-     * 
-     * @hide Pending API approval
+     * @see #getPersistedStringSet(Set)
      */
-    protected boolean persistStringSet(Set<String> values) {
+    public boolean persistStringSet(Set<String> values) {
         if (shouldPersist()) {
             // Shouldn't store null
             if (values.equals(getPersistedStringSet(null))) {
@@ -1527,10 +1525,8 @@
      * @return The value from the SharedPreferences or the default return
      *         value.
      * @see #persistStringSet(Set)
-     * 
-     * @hide Pending API approval
      */
-    protected Set<String> getPersistedStringSet(Set<String> defaultReturnValue) {
+    public Set<String> getPersistedStringSet(Set<String> defaultReturnValue) {
         if (!shouldPersist()) {
             return defaultReturnValue;
         }