otter.xml: Initialize for v1-u

<?xml version="1.0" encoding="UTF-8"?>

<manifest>

    <project name="e/devices/android_device_shift_otter" path="device/shift/otter" remote="e-priv"/>

    <project name="LineageOS/android_kernel_shift_qcm6490" path="kernel/shift/qcm6490" remote="github" revision="lineage-21" />

</manifest>