Add git.properties to default devtools excludes

Update `DevToolsProperties` to exclude `git.properties` files.

Prior to this commit any application configured to write `git.properties`
could trigger unexpected application restarts. The problem is particularly
prevalent when using Eclipse M2E in combination with the
`git-commit-id-plugin`.

Closes gh-3938

spring-boot-devtools/src/test/java/org/springframework/boot/devtools/autoconfigure/DevToolsPropertiesTests.java

@@ -38,7 +38,8 @@ public class DevToolsPropertiesTests {
 				restart.getAllExclude(),
 				arrayContaining("META-INF/maven/**", "META-INF/resources/**",
 						"resources/**", "static/**", "public/**", "templates/**",
-						"**/*Test.class", "**/*Tests.class", "foo/**", "bar/**"));
+						"**/*Test.class", "**/*Tests.class", "git.properties", "foo/**",
+						"bar/**"));
 	}
 
 	@Test