ANDROID: Add build.config files for ARM 32-bit

Enables us to catch build-breaks for 32-bit ARM with an allmodconfig
build in continuous integration testing.

Bug: 151459448
Change-Id: I825a18771c214e6389fc2755fce20c8fc2531695
Signed-off-by: Alistair Delva <adelva@google.com>
diff --git a/build.config.allmodconfig.arm b/build.config.allmodconfig.arm
new file mode 100644
index 0000000..5dd9481
--- /dev/null
+++ b/build.config.allmodconfig.arm
@@ -0,0 +1,4 @@
+. ${ROOT_DIR}/common/build.config.common
+. ${ROOT_DIR}/common/build.config.arm
+. ${ROOT_DIR}/common/build.config.allmodconfig
+