[wpilib] DriverStation: Change alliance station to use optional (#5229)

Many teams have issues trying to read the DS too early. By switching to an optional, we cause teams to check 2 things. Either 1) they explicitly check, and their code is correct, or 2) they just read .value() and their code reboots in a loop. However, because the DS will eventually connect, this 2nd case is ok, and should theoretically be undetectable on the field.

wpilibjExamples/src/test/java/edu/wpi/first/wpilibj/examples/i2ccommunication/I2CCommunicationTest.java

@@ -73,6 +73,9 @@ class I2CCommunicationTest {
 
     String str = assertTimeoutPreemptively(Duration.ofMillis(20L), () -> m_future.get());
     char expected = alliance.name().startsWith("Red") ? 'R' : 'B';
+    if (alliance.name().startsWith("Unknown")) {
+      expected = 'U';
+    }
 
     assertEquals(expected, str.charAt(0));
   }