Make Bazel always build with --fat_apk_cpu.

Also tweak the Android NDK CROSSTOOL file a bit so that it actually works.

Fixes #335.

--
MOS_MIGRATED_REVID=99377509
diff --git a/tools/cpp/BUILD b/tools/cpp/BUILD
index 240dc97..6599bc2 100644
--- a/tools/cpp/BUILD
+++ b/tools/cpp/BUILD
@@ -26,6 +26,7 @@
 filegroup(
     name = "toolchain",
     srcs = [
+        ":cc-compiler-armeabi-v7a",
         ":cc-compiler-darwin",
         ":cc-compiler-local",
         ":empty",
@@ -47,6 +48,20 @@
 )
 
 cc_toolchain(
+    name = "cc-compiler-armeabi-v7a",
+    all_files = ":empty",
+    compiler_files = ":empty",
+    cpu = "local",
+    dwp_files = ":empty",
+    dynamic_runtime_libs = [":empty"],
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    static_runtime_libs = [":empty"],
+    strip_files = ":empty",
+    supports_param_files = 0,
+)
+
+cc_toolchain(
     name = "cc-compiler-k8",
     all_files = ":empty",
     compiler_files = ":empty",
diff --git a/tools/cpp/CROSSTOOL b/tools/cpp/CROSSTOOL
index 583db2a..25368e9 100644
--- a/tools/cpp/CROSSTOOL
+++ b/tools/cpp/CROSSTOOL
@@ -14,6 +14,43 @@
   cpu: "darwin"
   toolchain_identifier: "local_darwin"
 }
+default_toolchain {
+  cpu: "armeabi-v7a"
+  toolchain_identifier: "stub_armeabi-v7a"
+}
+
+toolchain {
+  abi_version: "armeabi-v7a"
+  abi_libc_version: "armeabi-v7a"
+  builtin_sysroot: ""
+  compiler: "compiler"
+  host_system_name: "armeabi-v7a"
+  needsPic: true
+  supports_gold_linker: false
+  supports_incremental_linker: false
+  supports_fission: false
+  supports_interface_shared_objects: false
+  supports_normalizing_ar: false
+  supports_start_end_lib: false
+  supports_thin_archives: false
+  target_libc: "armeabi-v7a"
+  target_cpu: "armeabi-v7a"
+  target_system_name: "armeabi-v7a"
+  toolchain_identifier: "stub_armeabi-v7a"
+
+  tool_path { name: "ar" path: "/bin/false" }
+  tool_path { name: "compat-ld" path: "/bin/false" }
+  tool_path { name: "cpp" path: "/bin/false" }
+  tool_path { name: "dwp" path: "/bin/false" }
+  tool_path { name: "gcc" path: "/bin/false" }
+  tool_path { name: "gcov" path: "/bin/false" }
+  tool_path { name: "ld" path: "/bin/false" }
+
+  tool_path { name: "nm" path: "/bin/false" }
+  tool_path { name: "objcopy" path: "/bin/false" }
+  tool_path { name: "objdump" path: "/bin/false" }
+  tool_path { name: "strip" path: "/bin/false" }
+}
 
 toolchain {
   abi_version: "local"