build-unit-test-docker: meson 0.52.0 -> 0.53.2

This picks up fixes from upstream that we need to better support
subprojects in our repositories.

Change-Id: I103f1cd68d0899041d4a687b3a658068445d8834
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/build-unit-test-docker.sh b/build-unit-test-docker.sh
index 57a85ef..71aa626 100755
--- a/build-unit-test-docker.sh
+++ b/build-unit-test-docker.sh
@@ -253,7 +253,7 @@
 RUN pip install inflection
 RUN pip install pycodestyle
 RUN pip3 install inflection
-RUN pip3 install meson==0.52.0
+RUN pip3 install meson==0.53.2
 
 FROM openbmc-base as openbmc-lcov
 RUN curl -L https://github.com/linux-test-project/lcov/archive/${PKG_REV['lcov']}.tar.gz | tar -xz && \