Remove upgrade test related code

These were deleted in 2019 per 6e6e5f7

src/bosh-dev/lib/bosh/dev/sandbox/main.rb

@@ -35,8 +35,6 @@ class Main
     EXTERNAL_CPI_CONFIG = 'cpi.json'
     EXTERNAL_CPI_CONFIG_TEMPLATE = File.join(Bosh::Dev::ASSETS_DIR, 'cpi_config.json.erb')
 
-    UPGRADE_SPEC_ASSETS_DIR = File.join(Bosh::Dev::REPO_ROOT, 'spec', 'assets', 'upgrade')
-
     attr_reader :name
     attr_reader :health_monitor_process
     attr_reader :scheduler_process
@@ -173,10 +171,6 @@ def start
 
       @database.create_db
 
-      unless @test_initial_state.nil?
-        load_db_and_populate_blobstore(@test_initial_state)
-      end
-
       @config_server_service.start(@with_config_server_trusted_certs) if @config_server_enabled
 
       dir_config = director_config
@@ -316,7 +310,6 @@ def sandbox_root
     def reconfigure(options={})
       @user_authentication = options.fetch(:user_authentication, 'local')
       @config_server_enabled = options.fetch(:config_server_enabled, false)
-      @test_initial_state = options.fetch(:test_initial_state, nil)
       @with_config_server_trusted_certs = options.fetch(:with_config_server_trusted_certs, true)
       @director_fix_stateful_nodes = options.fetch(:director_fix_stateful_nodes, false)
       @dns_enabled = options.fetch(:dns_enabled, true)
@@ -412,25 +405,6 @@ def start_nats
 
     private
 
-    def load_db_and_populate_blobstore(test_initial_state)
-      @database.load_db_initial_state(File.join(UPGRADE_SPEC_ASSETS_DIR, test_initial_state))
-
-      if @database.adapter.eql? 'mysql2'
-        tar_filename = 'blobstore_snapshot_with_mysql.tar.gz'
-      elsif @database.adapter.eql? 'postgres'
-        tar_filename = 'blobstore_snapshot_with_postgres.tar.gz'
-      else
-        raise 'Pre-loading blobstore supported only for PostgresDB and MySQL'
-      end
-
-      blobstore_snapshot_path = File.join(UPGRADE_SPEC_ASSETS_DIR, test_initial_state, tar_filename)
-      @logger.info("Pre-filling blobstore '#{blobstore_storage_dir}' with blobs from '#{blobstore_snapshot_path}'")
-      tar_out = `tar xzvf #{blobstore_snapshot_path} -C #{blobstore_storage_dir}  2>&1`
-      if $?.exitstatus != 0
-        raise "Cannot pre-fill blobstore: #{tar_out}"
-      end
-    end
-
     def external_cpi_config
       {
         name: 'test-cpi',
@@ -454,8 +428,6 @@ def do_reset
       FileUtils.rm_rf(blobstore_storage_dir)
       FileUtils.mkdir_p(blobstore_storage_dir)
 
-      load_db_and_populate_blobstore(@test_initial_state) unless @test_initial_state.nil?
-
       stop_nats if @nats_process.running?
       start_nats