[release-12.3.2] Fix primary keys (#115884)

Convert unique keys in 3 tables to primary keys

pkg/services/sqlstore/migrator/testdata/sqlite_file_migration_statement.sql

@@ -0,0 +1,23 @@
+CREATE TABLE IF NOT EXISTS `file_new` (
+    `path` TEXT NOT NULL
+    , `path_hash` TEXT NOT NULL
+    , `parent_folder_path_hash` TEXT NOT NULL
+    , `contents` BLOB NOT NULL
+    , `etag` TEXT NOT NULL
+    , PRIMARY KEY ( `path_hash`,`etag` ));
+
+INSERT INTO `file_new` (`path`
+  , `path_hash`
+  , `parent_folder_path_hash`
+  , `contents`
+  , `etag`)
+SELECT `path`
+  , `path_hash`
+  , `parent_folder_path_hash`
+  , `contents`
+  , `etag`
+FROM `file`;
+
+DROP TABLE IF EXISTS `file`;
+ALTER TABLE `file_new` RENAME TO `file`;
+CREATE INDEX `IDX_file_parent_folder_path_hash` ON `file` (`parent_folder_path_hash`);