Fix failing docker build on Ubuntu 22.04

Running docker build on the provided Dockerfile is failing due to a missing dependency, libgnutls28-dev. Add it and also update the build commands to use apt-get instead of apt, as it is preferable to use apt-get when running in a non-interactive context like docker build.

Signed-off-by: Mukesh Sai Kumar <mukesh.kumar@dream11.com>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
diff --git a/building/Dockerfile.Ubuntu-22.04 b/building/Dockerfile.Ubuntu-22.04
index a9f629b..517e6bd 100644
--- a/building/Dockerfile.Ubuntu-22.04
+++ b/building/Dockerfile.Ubuntu-22.04
@@ -1,8 +1,8 @@
 FROM ubuntu:22.04
 ARG DEBIAN_FRONTEND=noninteractive
 ENV FORCE_UNSAFE_CONFIGURE=1
-RUN apt update && apt upgrade -y
-RUN apt install -y \
+RUN apt-get update && apt-get upgrade -y
+RUN apt-get install -y \
     adb \
     acpica-tools \
     autoconf \
@@ -22,6 +22,7 @@
     ftp-upload \
     gdisk \
     git \
+    libgnutls28-dev \
     libattr1-dev \
     libcap-ng-dev \
     libfdt-dev \