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 <[email protected]>

Author: adelva1984

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
+

build.config.arm

@@ -0,0 +1,12 @@
+ARCH=arm
+
+CLANG_TRIPLE=arm-linux-gnueabi-
+CROSS_COMPILE=arm-linux-androidkernel-
+LINUX_GCC_CROSS_COMPILE_PREBUILTS_BIN=prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/bin
+
+FILES="
+arch/arm/boot/Image.gz
+arch/arm/boot/Image
+vmlinux
+System.map
+"