add tests

Author: Jami Cogswell

java/ql/test/query-tests/Telemetry/SupportedExternalApis/SupportedExternalApis.expected

@@ -0,0 +1,3 @@
+| java.lang.StringBuilder#append(String) | 1 |
+| java.lang.StringBuilder#toString() | 1 |
+| java.util.Map#put(Object,Object) | 1 |

java/ql/test/query-tests/Telemetry/SupportedExternalApis/SupportedExternalApis.java

@@ -0,0 +1,16 @@
+import java.time.Duration;
+import java.util.HashMap;
+import java.util.Map;
+
+class SupportedExternalApis {
+	public static void main(String[] args) throws Exception {
+		StringBuilder builder = new StringBuilder();
+		builder.append("foo");  // supported
+		builder.toString();  // supported
+
+		Map<String, Object> map = new HashMap<>();
+		map.put("foo", new Object()); // supported
+
+		Duration d = java.time.Duration.ofMillis(1000); // not supported
+	}
+}

java/ql/test/query-tests/Telemetry/SupportedExternalApis/SupportedExternalApis.qlref

@@ -0,0 +1 @@
+Telemetry/SupportedExternalApis.ql