Add new error injection constant ERRINJ_AUTO_UPGRADE

In upgrade testing we need an ability to control running of upgrade.lua
script execution. When constant ERRINJ_AUTO_UPGRADE is set to true
tarantool will skip upgrade.lua script execution.

Part of #4801

src/box/lua/load_cfg.lua

@@ -588,7 +588,8 @@ local function load_cfg(cfg)
             end
         end
     end
-    if not box.cfg.read_only and not box.cfg.replication then
+    if not box.cfg.read_only and not box.cfg.replication and
+       not box.error.injection.get('ERRINJ_AUTO_UPGRADE') then
         box.schema.upgrade{auto = true}
     end
 end

src/lib/core/errinj.h

@@ -144,6 +144,7 @@ struct errinj {
 	_(ERRINJ_VY_READ_VIEW_MERGE_FAIL, ERRINJ_BOOL, {.bparam = false})\
 	_(ERRINJ_VY_WRITE_ITERATOR_START_FAIL, ERRINJ_BOOL, {.bparam = false})\
 	_(ERRINJ_VY_RUN_OPEN, ERRINJ_INT, {.iparam = -1})\
+	_(ERRINJ_AUTO_UPGRADE, ERRINJ_BOOL, {.bparam = false})\
 
 ENUM0(errinj_id, ERRINJ_LIST);
 extern struct errinj errinjs[];

test/box/errinj.result

@@ -43,7 +43,8 @@ end
 ...
 evals
 ---
-- - ERRINJ_BUILD_INDEX: -1
+- - ERRINJ_AUTO_UPGRADE: false
+  - ERRINJ_BUILD_INDEX: -1
   - ERRINJ_BUILD_INDEX_DELAY: false
   - ERRINJ_CHECK_FORMAT_DELAY: false
   - ERRINJ_COIO_SENDFILE_CHUNK: -1