Use armv7- not arm-; drop mips support.

Per rust-lang/rust#33278,
`armv7-android-linuxeabi` is preferred to `arm-android-linuxeabi`.

Per https://developer.android.com/ndk/guides/abis: "Historically the
NDK supported 32-bit and 64-bit MIPS, but support was removed in NDK
r17."

Author: ncalexan

README.md

@@ -7,18 +7,18 @@ Cross compiles rust cargo projects for Android
 To begin you must first install the rust toolchains for your target platforms.
 
 ```
-rustup target add arm-linux-androideabi     # for arm
+rustup target add armv7-linux-androideabi   # for arm
 rustup target add i686-linux-android        # for x86
 ...
 ```
 
 Next add the `cargo` configuration to android project. Point to your cargo project using `module` and add targets.
-Currently supported targets are `arm`, `arm64`, `mips`, and `x86`, `x86_64`.
+Currently supported targets are `arm`, `arm64` and `x86`, `x86_64`.
 
 ```
 cargo {
     module = "../rust"
-    targets = ["arm", "x84"]
+    targets = ["arm", "x86"]
 }
 
 ```

plugin/src/main/kotlin/com/nishtahir/RustAndroidPlugin.kt

@@ -16,7 +16,7 @@ val toolchains = listOf(
                 "<ar>",
                 "default"),
         Toolchain("arm",
-                "arm-linux-androideabi",
+                "armv7-linux-androideabi",
                 "bin/arm-linux-androideabi-clang",
                 "bin/arm-linux-androideabi-ar",
                 "armeabi-v7a"),
@@ -25,11 +25,6 @@ val toolchains = listOf(
                 "bin/aarch64-linux-android-clang",
                 "bin/aarch64-linux-android-ar",
                 "arm64-v8a"),
-        Toolchain("mips",
-                "mipsel-linux-android",
-                "bin/mipsel-linux-android-clang",
-                "bin/mipsel-linux-android-ar",
-                "mips"),
         Toolchain("x86",
                 "i686-linux-android",
                 "bin/i686-linux-android-clang",