scripts/build-unit-test-docker: Upgrade to gcc11

This is used by the latest poky change and we want to make sure our code
is compatible prior to submission.

Change-Id: Ife93b2810bcfc6e50a89f06268b082e6cf5426fd
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/scripts/build-unit-test-docker b/scripts/build-unit-test-docker
index 440022a..e6d119d 100755
--- a/scripts/build-unit-test-docker
+++ b/scripts/build-unit-test-docker
@@ -733,8 +733,8 @@
 RUN cat /etc/apt/sources.list.d/debug.list
 
 RUN apt-get update && apt-get dist-upgrade -yy && apt-get install -yy \
-    gcc-10 \
-    g++-10 \
+    gcc-11 \
+    g++-11 \
     libc6-dbg \
     libc6-dev \
     libtool \
@@ -796,11 +796,11 @@
     libxml-simple-perl \
     rsync
 
-RUN update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-10 1000 \
-  --slave /usr/bin/g++ g++ /usr/bin/g++-10 \
-  --slave /usr/bin/gcov gcov /usr/bin/gcov-10 \
-  --slave /usr/bin/gcov-dump gcov-dump /usr/bin/gcov-dump-10 \
-  --slave /usr/bin/gcov-tool gcov-tool /usr/bin/gcov-tool-10
+RUN update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-11 11 \
+  --slave /usr/bin/g++ g++ /usr/bin/g++-11 \
+  --slave /usr/bin/gcov gcov /usr/bin/gcov-11 \
+  --slave /usr/bin/gcov-dump gcov-dump /usr/bin/gcov-dump-11 \
+  --slave /usr/bin/gcov-tool gcov-tool /usr/bin/gcov-tool-11
 
 RUN update-alternatives --install /usr/bin/clang clang /usr/bin/clang-11 1000 \
   --slave /usr/bin/clang++ clang++ /usr/bin/clang++-11 \