fix: flaky test issue due to AbortedException. (#2925)

* fix: prevent illegal negative timeout values into thread sleep() method while retrying exceptions in unit tests. * For details on issue see - #2206 * Fixing lint issues. * fix: flaky test issue due to AbortedException. * chore: remove assertion.

Author: arpan14

google-cloud-spanner/src/test/java/com/google/cloud/spanner/it/ITTransactionTest.java

@@ -298,7 +298,6 @@ public void readAbort() throws Exception {
  } catch (SpannerException e) {
  if (e.getErrorCode() == ErrorCode.ABORTED) {
  assertThat(e).isInstanceOf(AbortedException.class);
- assertThat(e.getRetryDelayInMillis()).isNotEqualTo(-1L);
  }
  throw new RuntimeException("Swallowed exception: " + e.getMessage());
  }
@@ -338,7 +337,6 @@ public void readAbort() throws Exception {
  } catch (SpannerException e) {
  if (e.getErrorCode() == ErrorCode.ABORTED) {
  assertThat(e).isInstanceOf(AbortedException.class);
- assertThat(e.getRetryDelayInMillis()).isNotEqualTo(-1L);
  }
  throw new RuntimeException("Swallowed exception: " + e.getMessage());
  }