fix(samples): Use float literal for session-replay sample rate (#5764)

The Android sample manifest set io.sentry.session-replay.session-sample-rate
to the integer literal "1", which aapt stores as an int. ManifestMetadataReader
reads it via Bundle.getFloat, which does not coerce an int-typed value and logs
a framework warning before falling back to getInt on startup. Using the float
literal "1.0" stores it as a float so getFloat succeeds and no warning is logged.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>