Fix potential ArrayIndexOutOfBoundsException.

When parsing an SMS message as email, extractEmailAddressFromMessageBody()
checks parts.length >= 1, but then proceeds to access parts[1] (which
may not exist).  Instead, check for parts.length >= 2, and treat
parts.length = 1 as non-email.

b/2122698

telephony/java/com/android/internal/telephony/SmsMessageBase.java

@@ -383,7 +383,7 @@ public abstract class SmsMessageBase {
          * 2. [x@y][ ]/[body]
          */
          String[] parts = messageBody.split("( /)|( )", 2);
-         if (parts.length < 1) return;
+         if (parts.length < 2) return;
          emailFrom = parts[0];
          emailBody = parts[1];
          isEmail = true;