Move Scoped Storage compat flags definition to  frameworks/base

Currently the flags definition is in MediaProvider, which is an
apex module (updatable), and the flags values are now used in
frameworks/base as well (non-updatable).

Good to have flags definition in the constant component.

Bug: 150593967
Test: atest ExternalStorageHostTest
Test: atest com.android.providers.media
Test: manual
Merged-In: I0b06c068cb3957a7db8af5e14598724f72122736
Change-Id: I0b06c068cb3957a7db8af5e14598724f72122736
(cherry picked from commit 4a989379e84d75e4970c3a7b77a1ea64f2fb59b5)
diff --git a/core/java/android/os/Environment.java b/core/java/android/os/Environment.java
index 09ccb72..ae65f1d 100644
--- a/core/java/android/os/Environment.java
+++ b/core/java/android/os/Environment.java
@@ -24,6 +24,8 @@
 import android.app.AppOpsManager;
 import android.app.admin.DevicePolicyManager;
 import android.compat.Compatibility;
+import android.compat.annotation.ChangeId;
+import android.compat.annotation.Disabled;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.Context;
 import android.content.Intent;
@@ -90,13 +92,43 @@
             "/apex");
 
     /**
-     * See definition in com.android.providers.media.LocalCallingIdentity
+     * Scoped Storage is on by default. However, it is not strictly enforced and there are multiple
+     * ways to opt out of scoped storage:
+     * <ul>
+     * <li>Target Sdk < Q</li>
+     * <li>Target Sdk = Q and has `requestLegacyExternalStorage` set in AndroidManifest.xml</li>
+     * <li>Target Sdk > Q: Upgrading from an app that was opted out of scoped storage and has
+     * `preserveLegacyExternalStorage` set in AndroidManifest.xml</li>
+     * </ul>
+     * This flag is enabled for all apps by default as Scoped Storage is enabled by default.
+     * Developers can disable this flag to opt out of Scoped Storage and have legacy storage
+     * workflow.
+     *
+     * Note: {@code FORCE_ENABLE_SCOPED_STORAGE} should also be disabled for apps to opt out of
+     * scoped storage.
+     * Note: This flag is also used in {@code com.android.providers.media.LocalCallingIdentity}.
+     * Any modifications to this flag should be reflected there as well.
+     * See https://developer.android.com/training/data-storage#scoped-storage for more information.
      */
+    @ChangeId
     private static final long DEFAULT_SCOPED_STORAGE = 149924527L;
 
     /**
-     * See definition in com.android.providers.media.LocalCallingIdentity
+     * Setting this flag strictly enforces Scoped Storage regardless of:
+     * <ul>
+     * <li>The value of Target Sdk</li>
+     * <li>The value of `requestLegacyExternalStorage` in AndroidManifest.xml</li>
+     * <li>The value of `preserveLegacyExternalStorage` in AndroidManifest.xml</li>
+     * </ul>
+     *
+     * Note: {@code DEFAULT_SCOPED_STORAGE} should also be enabled for apps to be enforced into
+     * scoped storage.
+     * Note: This flag is also used in {@code com.android.providers.media.LocalCallingIdentity}.
+     * Any modifications to this flag should be reflected there as well.
+     * See https://developer.android.com/training/data-storage#scoped-storage for more information.
      */
+    @ChangeId
+    @Disabled
     private static final long FORCE_ENABLE_SCOPED_STORAGE = 132649864L;
 
     @UnsupportedAppUsage