add Seedvault as backup provider

[dslul]

These changes (see also 1 and 2) add support for Seedvault, a backup app that integrates in the system directly.
I've been using it since September in an Android 10 build and works flawlessly. It's also used now in the official Lineageos builds.

[bartcubbins]

Thanks for the contribution!
I don't mind having Seedvault in our ROM, just let's do everything properly. Below I indicated the correct version of your patch, please update your PR in accordance with it

From e44bb599620afb055208b560831916fe7361b4b6 Mon Sep 17 00:00:00 2001
From: Pavel Dubrova <pashadubrova@gmail.com>
Date: Wed, 3 Feb 2021 18:33:31 +0200
Subject: [PATCH] SettingsProvider: Add ability to change default backup
 provider

Signed-off-by: Pavel Dubrova <pashadubrova@gmail.com>
---
 .../providers/settings/SettingsProvider.java  | 27 ++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java b/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
index b95d34f2966..ca842b4e834 100644
--- a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
+++ b/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
@@ -3513,7 +3513,7 @@ public class SettingsProvider extends ContentProvider {
         }
 
         private final class UpgradeController {
-            private static final int SETTINGS_VERSION = 191;
+            private static final int SETTINGS_VERSION = 192;
 
             private final int mUserId;
 
@@ -4882,6 +4882,31 @@ public class SettingsProvider extends ContentProvider {
                     currentVersion = 191;
                 }
 
+                if (currentVersion == 191) {
+                    // Version 191: Update default Backup app
+                    final SettingsState secureSettings = getSecureSettingsLocked(userId);
+                    final Setting currentBackupTransportSetting = secureSettings.getSettingLocked(
+                            Secure.BACKUP_TRANSPORT);
+                    if (currentBackupTransportSetting.isDefaultFromSystem()) {
+                        secureSettings.insertSettingLocked(
+                                Settings.Secure.BACKUP_TRANSPORT,
+                                getContext().getResources().getString(
+                                        R.string.def_backup_transport),
+                                null, true, SettingsState.SYSTEM_PACKAGE_NAME);
+                    }
+
+                    final Setting currentBackupEnabledSetting = secureSettings.getSettingLocked(
+                            Secure.BACKUP_ENABLED);
+                    if (currentBackupEnabledSetting.isDefaultFromSystem()) {
+                        secureSettings.insertSettingLocked(
+                                Settings.Secure.BACKUP_ENABLED,
+                                getContext().getResources().getBoolean(
+                                        R.bool.def_backup_enabled)? "1" : "0",
+                                null, true, SettingsState.SYSTEM_PACKAGE_NAME);
+                    }
+                    currentVersion = 192;
+                }
+
                 // vXXX: Add new settings above this point.
 
                 if (currentVersion != newVersion) {
-- 
2.30.0

[bartcubbins]

You need to create an overlay in this repository and put it there
https://github.com/ExplosiveLobster/platform_vendor_el