Fix tempdir failure in TestInitDatabaseService (#50717)

* Reduce flakiness in TestInitDatabaseService

This test was setting the auth's storage config to use a different
temp dir than the backend's storage dir, which could result in the
non-empty directory that fails during cleanup.

As of #48247 tests don't need to set this at all since the default
behavior now does the right thing.

* Apply the same fix to a few other tests

lib/service/service_test.go

@@ -109,7 +109,6 @@ func TestAdditionalExpectedRoles(t *testing.T) {
 				cfg := servicecfg.MakeDefaultConfig()
 				cfg.DataDir = makeTempDir(t)
 				cfg.SetAuthServerAddress(utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"})
-				cfg.Auth.StorageConfig.Params["path"] = t.TempDir()
 				cfg.DiagnosticAddr = utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"}
 				cfg.Auth.ListenAddr = utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"}
 
@@ -140,7 +139,6 @@ func TestAdditionalExpectedRoles(t *testing.T) {
 				cfg := servicecfg.MakeDefaultConfig()
 				cfg.DataDir = makeTempDir(t)
 				cfg.SetAuthServerAddress(utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"})
-				cfg.Auth.StorageConfig.Params["path"] = t.TempDir()
 				cfg.DiagnosticAddr = utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"}
 				cfg.Auth.ListenAddr = utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"}
 
@@ -284,7 +282,6 @@ func TestMonitor(t *testing.T) {
 	cfg.DiagnosticAddr = utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"}
 	cfg.SetAuthServerAddress(utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"})
 	cfg.Auth.Enabled = true
-	cfg.Auth.StorageConfig.Params["path"] = t.TempDir()
 	cfg.Auth.ListenAddr = utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"}
 	cfg.Proxy.Enabled = false
 	cfg.SSH.Enabled = false
@@ -1746,7 +1743,6 @@ func TestInstanceMetadata(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			cfg := newCfg()
 			cfg.DataDir = makeTempDir(t)
-			cfg.Auth.StorageConfig.Params["path"] = t.TempDir()
 			cfg.InstanceMetadataClient = tc.imClient
 
 			process, err := NewTeleport(cfg)
@@ -1811,12 +1807,10 @@ func TestInitDatabaseService(t *testing.T) {
 			cfg.DebugService = servicecfg.DebugConfig{
 				Enabled: false,
 			}
-			cfg.Auth.StorageConfig.Params["path"] = t.TempDir()
 			cfg.Hostname = "default.example.com"
 			cfg.Auth.Enabled = true
 			cfg.SetAuthServerAddress(utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"})
 			cfg.Auth.ListenAddr = utils.NetAddr{AddrNetwork: "tcp", Addr: "127.0.0.1:0"}
-			cfg.Auth.StorageConfig.Params["path"] = t.TempDir()
 			cfg.Auth.SessionRecordingConfig.SetMode(types.RecordOff)
 			cfg.Proxy.Enabled = true
 			cfg.Proxy.DisableWebInterface = true