fix: update XML element retrieval to use correct parent nodes

[aytee6]

Handling the case when the network security configs already exist under the <debug-overrides/> element.
We should look for the next element under the new element we created/found.

Currently:

<network-security-config>
    <debug-overrides>
        <trust-anchors>
            <certificates src="user" />
            <certificates src="system" /> --- Added line
        </trust-anchors>
    </debug-overrides>
    <base-config /> --- Added line
</network-security-config>

Expected:

<network-security-config>
    <debug-overrides>
        <trust-anchors>
            <certificates src="user" />
        </trust-anchors>
    </debug-overrides>
    <base-config>
        <trust-anchors>
            <certificates src="system" />
            <certificates src="user" />
        </trust-anchors>
    </base-config>
</network-security-config>

Example package: com.tradingview.tradingviewapp