Fix Android toolchain selection

Both `armv7` and `thumbv7neon` generate Thumb code, the only difference is Neon.

Author: FooIbar

cmake/FindRust.cmake

@@ -735,10 +735,10 @@ if (NOT Rust_CARGO_TARGET_CACHED)
         endif()
     elseif (ANDROID)
         if (CMAKE_ANDROID_ARCH_ABI STREQUAL armeabi-v7a)
-            if (CMAKE_ANDROID_ARM_MODE)
-                set(_Rust_ANDROID_TARGET armv7-linux-androideabi)
-            else ()
+            if (CMAKE_ANDROID_ARM_NEON)
                 set(_Rust_ANDROID_TARGET thumbv7neon-linux-androideabi)
+            else ()
+                set(_Rust_ANDROID_TARGET armv7-linux-androideabi)
             endif()
         elseif (CMAKE_ANDROID_ARCH_ABI STREQUAL arm64-v8a)
             set(_Rust_ANDROID_TARGET aarch64-linux-android)