java:chore - Adding improvements on Java Rules

In this commit I changed to add Safe and Unsafe code in
all rules of the java. Reference from issue #630 and #1020.

Signed-off-by: Wilian Gabriel <wilian.silva@zup.com.br>

internal/services/engines/dart/rules.go

@@ -73,8 +73,10 @@ Depending on the implementation in the operating system the bioID is just a lock
 Basically on Android, you can ask to use the 4-digit password because of "faulty hardware" and this functionality depends on how the application uses this.
 There are applications that ask for 6 digit passwords and then ask for the bioID just to "automatically type" the 6 digit password which can cause an easy identification and access to your application is broken.
 For more information checkout the OWSAP M4:2016 (https://owasp.org/www-project-mobile-top-10/2016-risks/m4-insecure-authentication) advisory and see this example how implement good authentication (in "C" Language): https://developer.apple.com/library/archive/samplecode/KeychainTouchID/Introduction/Intro.html.`,
-			Severity:   severities.Info.ToString(),
-			Confidence: confidence.Medium.ToString(),
+			Severity:      severities.Info.ToString(),
+			Confidence:    confidence.Medium.ToString(),
+			SafeExample:   SampleSafeHSDART3,
+			UnsafeExample: SampleVulnerableHSDART3,
 		},
 		Type: text.AndMatch,
 		Expressions: []*regexp.Regexp{

internal/services/engines/dart/rules_test.go

@@ -116,7 +116,7 @@ func TestRulesVulnerableCode(t *testing.T) {
 					CodeSample: "import 'package:flutter_sms/flutter_sms.dart';",
 					SourceLocation: engine.Location{
 						Filename: filepath.Join(tempDir, "HS-DART-6.test"),
-						Line:     1,
+						Line:     2,
 						Column:   28,
 					},
 				},
@@ -329,7 +329,7 @@ func TestRulesSafeCode(t *testing.T) {
 		{
 			Name:     "HS-DART-3",
 			Rule:     NewNoUseBiometricsTypeIOS(),
-			Src:      "",
+			Src:      SampleSafeHSDART3,
 			Filename: filepath.Join(tempDir, "HS-DART-3.test"),
 		},
 		{