Rename metricAssert -> metric in failsafe-3.0 and iceberg-1.8 tests

No behavioral change; pure rename of lambda variable to match repo convention
of short names (metric, sum, gauge, point).

Author: trask

instrumentation/failsafe-3.0/library/src/test/java/io/opentelemetry/instrumentation/failsafe/v3_0/FailsafeTelemetryTest.java

@@ -54,8 +54,8 @@ void captureCircuitBreakerMetrics() {
     // then
     testing.waitAndAssertMetrics(
         "io.opentelemetry.failsafe-3.0",
-        metricAssert ->
-            metricAssert
+        metric ->
+            metric
                 .hasName("failsafe.circuit_breaker.execution.count")
                 .hasLongSumSatisfying(
                     sum ->
@@ -65,8 +65,8 @@ void captureCircuitBreakerMetrics() {
                                     2, "failsafe.circuit_breaker.outcome", "failure"),
                                 buildCircuitBreakerAssertion(
                                     3, "failsafe.circuit_breaker.outcome", "success"))),
-        metricAssert ->
-            metricAssert
+        metric ->
+            metric
                 .hasName("failsafe.circuit_breaker.state_change.count")
                 .hasLongSumSatisfying(
                     sum ->
@@ -108,17 +108,17 @@ void captureRetryPolicyMetrics() {
     // then
     testing.waitAndAssertMetrics(
         "io.opentelemetry.failsafe-3.0",
-        metricAssert ->
-            metricAssert
+        metric ->
+            metric
                 .hasName("failsafe.retry_policy.execution.count")
                 .hasLongSumSatisfying(
                     sum ->
                         sum.isMonotonic()
                             .hasPointsSatisfying(
                                 buildRetryPolicyAssertion(2, "failure"),
                                 buildRetryPolicyAssertion(3, "success"))),
-        metricAssert ->
-            metricAssert
+        metric ->
+            metric
                 .hasName("failsafe.retry_policy.attempts")
                 .hasHistogramSatisfying(
                     histogramAssert ->

instrumentation/iceberg-1.8/testing/src/main/java/io/opentelemetry/instrumentation/iceberg/v1_8/AbstractIcebergTest.java

@@ -111,8 +111,8 @@ private void assertScanDurationMetric(ScanReport expectedReport) {
     testing()
         .waitAndAssertMetrics(
             "io.opentelemetry.iceberg-1.8",
-            metricAssert ->
-                metricAssert
+            metric ->
+                metric
                     .hasName("iceberg.scan.planning.duration")
                     .hasUnit("s")
                     .hasHistogramSatisfying(
@@ -135,8 +135,8 @@ private void assertDataFilesCountMetrics(ScanReport expectedReport) {
     testing()
         .waitAndAssertMetrics(
             "io.opentelemetry.iceberg-1.8",
-            metricAssert ->
-                metricAssert
+            metric ->
+                metric
                     .hasName("iceberg.scan.data_files.count")
                     .hasUnit("{file}")
                     .hasLongSumSatisfying(
@@ -172,8 +172,8 @@ private void assertDataManifestCountMetrics(ScanReport expectedReport) {
     testing()
         .waitAndAssertMetrics(
             "io.opentelemetry.iceberg-1.8",
-            metricAssert ->
-                metricAssert
+            metric ->
+                metric
                     .hasName("iceberg.scan.data_manifests.count")
                     .hasUnit("{file}")
                     .hasLongSumSatisfying(
@@ -215,8 +215,8 @@ private void assertDeleteManifestCountMetrics(ScanReport expectedReport) {
     testing()
         .waitAndAssertMetrics(
             "io.opentelemetry.iceberg-1.8",
-            metricAssert ->
-                metricAssert
+            metric ->
+                metric
                     .hasName("iceberg.scan.delete_manifests.count")
                     .hasUnit("{file}")
                     .hasLongSumSatisfying(
@@ -258,8 +258,8 @@ private void assertDeleteFilesCountMetrics(ScanReport expectedReport) {
     testing()
         .waitAndAssertMetrics(
             "io.opentelemetry.iceberg-1.8",
-            metricAssert ->
-                metricAssert
+            metric ->
+                metric
                     .hasName("iceberg.scan.delete_files.count")
                     .hasUnit("{file}")
                     .hasLongSumSatisfying(
@@ -367,8 +367,8 @@ private void assertSizeMetric(
     testing()
         .waitAndAssertMetrics(
             "io.opentelemetry.iceberg-1.8",
-            metricAssert ->
-                metricAssert
+            metric ->
+                metric
                     .hasName(otelMetricName)
                     .hasUnit("By")
                     .hasLongSumSatisfying(