Add brazilian portuguese string translation.

app/src/main/res/values-pt-rBR/strings.xml

+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+
+    <!-- Titles -->
+    <string name="title_sign_in_your_server">Faça login no seu servidor</string>
+    <string name="title_log_in">Entrar</string>
+    <string name="title_sign_up">Inscreva-se</string>
+
+    <!-- Actions -->
+    <string name="action_connect">Conectar</string>
+
+    <!-- Regular information messages -->
+    <string name="msg_username">nome de usuário</string>
+    <string name="msg_password">senha</string>
+    <string name="msg_name">nome</string>
+    <string name="msg_new_in_rocket_chat">Novo no Rocket Chat?</string>
+    <string name="msg_2fa_code">Código 2FA</string>
+
+</resources>
\ No newline at end of file