html5+ 不能调用前置摄像头

示例代码：

const cmr = plus.camera.getCamera(2);
const res = cmr.supportedImageResolutions[0];
const fmt = cmr.supportedImageFormats[0];
cmr.captureImage(p => {
plus.io.resolveLocalFileSystemURL(p, entry => {
this.compressImage(entry.toLocalURL(), entry.name);
}, function(e) {
plus.nativeUI.toast("读取拍照文件错误：" + e.message);
});
}, e => {},{
index:"2"
});

操作步骤：

const cmr = plus.camera.getCamera(2);
const res = cmr.supportedImageResolutions[0];
const fmt = cmr.supportedImageFormats[0];
cmr.captureImage(p => {
plus.io.resolveLocalFileSystemURL(p, entry => {
this.compressImage(entry.toLocalURL(), entry.name);
}, function(e) {
plus.nativeUI.toast("读取拍照文件错误：" + e.message);
});
}, e => {},{
index:"2"
});

预期结果：

希望能让anroid支持调用前置摄像头进行人脸自拍。

实际结果：

const cmr = plus.camera.getCamera(2);
const res = cmr.supportedImageResolutions[0];
const fmt = cmr.supportedImageFormats[0];
cmr.captureImage(p => {
plus.io.resolveLocalFileSystemURL(p, entry => {
this.compressImage(entry.toLocalURL(), entry.name);
}, function(e) {
plus.nativeUI.toast("读取拍照文件错误：" + e.message);
});
}, e => {},{
index:"2"
});