chore(java): attempt to reduce flaky CI failures (#2203)

Author: sharmabikram

.github/workflows/ci_test_vector_java.yml

@@ -26,6 +26,7 @@ on:
 jobs:
   testJava:
     strategy:
+      fail-fast: false
       matrix:
         library: [TestVectors]
         java-version: [8, 11, 17, 19]

DynamoDbEncryption/runtimes/java/src/test/sdkv1/com/amazonaws/services/dynamodbv2/datamodeling/encryption/providers/CachingMostRecentProviderTests.java

@@ -190,8 +190,9 @@ public void testSingleVersion() throws InterruptedException {
       0,
       store.getVersionFromMaterialDescription(eMat2.getMaterialDescription())
     );
-    // Let the TTL be exceeded
-    Thread.sleep(500);
+    // Let the TTL be exceeded; sleep must be > TTL (500ms) to reliably
+    // land in the grace period and trigger a cache refresh.
+    Thread.sleep(700);
     final EncryptionMaterials eMat3 = prov.getEncryptionMaterials(ctx);
     assertEquals(2, methodCalls.size());
     assertEquals(1, (int) methodCalls.getOrDefault("query", 0)); // To find current version
@@ -356,8 +357,9 @@ public void testTwoVersions() throws InterruptedException {
       "Expected no calls but was " + methodCalls.toString(),
       methodCalls.isEmpty()
     );
-    // Let the TTL be exceeded
-    Thread.sleep(500);
+    // Let the TTL be exceeded; sleep must be > TTL (500ms) to reliably
+    // land in the grace period and trigger a cache refresh.
+    Thread.sleep(700);
     final EncryptionMaterials eMat3 = prov.getEncryptionMaterials(ctx);
 
     assertEquals(1, (int) methodCalls.getOrDefault("query", 0)); // To find current version
@@ -512,8 +514,9 @@ public void testSingleVersionTwoMaterials() throws InterruptedException {
       store.getVersionFromMaterialDescription(eMat2_2.getMaterialDescription())
     );
 
-    // Let the TTL be exceeded
-    Thread.sleep(500);
+    // Let the TTL be exceeded; sleep must be > TTL (500ms) to reliably
+    // land in the grace period and trigger a cache refresh.
+    Thread.sleep(700);
     final EncryptionMaterials eMat3_1 = prov.getEncryptionMaterials(ctx1);
     assertEquals(2, methodCalls.size());
     assertEquals(1, (int) methodCalls.get("query")); // To find current version