Android hardcodes six battery notification strings as Kotlin literals, so they ship English in every locale #867

Mirror image of the Apple gap fixed in #866.

android/app/src/main/java/com/noop/notif/BatteryAlertNotifier.kt builds three of its five battery
notifications from raw Kotlin string literals rather than R.string, so they are untranslatable and
ship English in all five shipped locales:

123  .setContentTitle("Strap battery low")
124  .setContentText("$label left on your WHOOP — recharge tonight.")
151  .setContentTitle("Low battery")
152  .setContentText("Recharge your WHOOP before tonight.")
163  .setContentTitle("Strap fully charged")
164  .setContentText("Your WHOOP is at 100%.")

The two escalations #864 added (battery_critical_*, battery_bedtime_*) do it correctly via
context.getString(...), so this is the older code, not a regression from that PR.

All six have Apple counterparts translated into all eight languages — four were already in the
catalog, the other two landed in #866 — so the English wording and the translations already exist
and only need moving into values/strings.xml plus the five locale files.

Suggested shape

Add battery_runtime_title / battery_runtime_body (%1$s), battery_low_title /
battery_low_body, battery_full_title / battery_full_body alongside the existing
battery_critical_* and battery_bedtime_* keys, and swap the six call sites to getString.

Two things to get right:

• "Your WHOOP is at 100%." needs its percent escaped as 100%% in strings.xml, since the
  Android resource is a format string.
• Register: this catalog is informal in es and pt-PT (see the counts in Localize the battery notification strings that never reached the Apple catalog #866), and the strings
  imported from Apple should stay that way. Escalate strap battery alerts: a critical 12% crossing + a bedtime night-guard (Swift + Kotlin) #864's battery_critical_* and battery_bedtime_* are
  currently formal in those two locales, so once these six land beside them the mismatch becomes
  visible within a single file — worth aligning in the same PR.

Nothing compiles Android in CI today (android.yml is disabled_manually), so whoever takes this
should run ./gradlew compileFullDebugKotlin locally and say so.