fix(internal/gensupport): don't prematurely close timers (#1856)

quitAfterTimer should only be closed when function breaks or
returns as it is created outside of the for loop. Tested with
local replacing and fixes failing TestIndefiniteRetries test with
the patch.

Updates: googleapis/google-cloud-go#7410

internal/gensupport/resumable.go

@@ -209,7 +209,6 @@ func (rx *ResumableUpload) Upload(ctx context.Context) (resp *http.Response, err
 				}
 				return prepareReturn(resp, err)
 			case <-pauseTimer.C:
-				quitAfterTimer.Stop()
 			case <-quitAfterTimer.C:
 				pauseTimer.Stop()
 				return prepareReturn(resp, err)
@@ -231,7 +230,6 @@ func (rx *ResumableUpload) Upload(ctx context.Context) (resp *http.Response, err
 			case <-quitAfterTimer.C:
 				return prepareReturn(resp, err)
 			default:
-				quitAfterTimer.Stop()
 			}
 
 			resp, err = rx.transferChunk(ctx)
@@ -243,6 +241,7 @@ func (rx *ResumableUpload) Upload(ctx context.Context) (resp *http.Response, err
 
 			// Check if we should retry the request.
 			if !errorFunc(status, err) {
+				quitAfterTimer.Stop()
 				break
 			}