[FIX] theme_kea: fix the data of shape on s_picture in KEA theme

Commit [1] refreshed the design of the KEA theme but unfortunately
introduced the wrong path to a shape on the s_picture snippet.

This used to cause a traceback but [2] fixed it. However, it is still
worth correcting the path so that shapes automatically chain under the
s_picture snippet of that theme.

To do so, a simple check is added when the option computes the next
shape, and looks for the broken path, if it finds it, it corrects it.

Steps to reproduce:
- Use the KEA theme
- Drop the "Picture" snippet
- Drop the text snippet under it
- Enable the background shape option for the text snippet
- The first shape is selected instead of the next one in the series.

To fix properly in master of course.

[1]: https://github.com/odoo/design-themes/commit/88b81d41dadbfaad5d0b36ba2f1c595e309438ba
[2]: https://github.com/odoo/odoo/commit/e985f8ef7a358c5aae9245267e18e65ea8383400

opw-3082292

closes odoo/design-themes#619

Related: odoo/odoo#107224
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

theme_kea/views/snippets/s_picture.xml

@@ -5,6 +5,7 @@
     <!-- Section -->
     <xpath expr="//section" position="attributes">
         <attribute name="class" add="o_cc3" remove="o_cc2" separator=" "/>
+        <!-- TODO: adapt in master, this was fixed in JS -->
         <attribute name="data-oe-shape-data">{"shape":"web_editor/Origins/Wavy_03","flip":["y"]}</attribute>
     </xpath>
     <!-- Shape -->