I am pretty sure it's in the right place. But I'm seeing now that neither of the two upgrades in there are working. Neither the galley nor liburna will upgrade to anything. Here, take a look at my units.xml file. Keep in mind that all the units work, just not the upgrades.
I have not checked to see if galley upgrades to caravel because I don't have that tech in my test game and I don't want to click next turn 100 more times.
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<GameInfo>
<Types>
<Row Type="UNIT_BIREME" Kind="KIND_UNIT"/>
<Row Type="UNIT_DECERES" Kind="KIND_UNIT"/>
<Row Type="UNIT_HERBALIST" Kind="KIND_UNIT"/>
<Row Type="UNIT_HORSE_ARCHER" Kind="KIND_UNIT"/>
<Row Type="UNIT_LIBURNA" Kind="KIND_UNIT"/>
</Types>
<Units>
<Update>
<Where UnitType="UNIT_BATTERING_RAM"/>
<Set PrereqTech="TECH_THE_WHEEL"/>
</Update>
<Update>
<Where UnitType="UNIT_GALLEY"/>
<Set BaseMoves="2"/>
</Update>
<Update>
<Where UnitType="UNIT_GALLEY"/>
<Set Cost="60"/>
</Update>
<Update>
<Where UnitType="UNIT_GALLEY"/>
<Set Combat="20"/>
</Update>
<Update>
<Where UnitType="UNIT_QUADRIREME"/>
<Set Combat="30"/>
</Update>
<Update>
<Where UnitType="UNIT_QUADRIREME"/>
<Set RangedCombat="20"/>
</Update>
<Update>
<Where UnitType="UNIT_SPEARMAN"/>
<Set RangedCombat="10"/>
</Update>
<Update>
<Where UnitType="UNIT_SPEARMAN"/>
<Set Range="1"/>
</Update>
<Row UnitType="UNIT_BIREME" BaseMoves="3" Cost="90" AdvisorType="ADVISOR_CONQUEST" BaseSightRange="2" ZoneOfControl="true" Domain="DOMAIN_SEA" FormationClass="FORMATION_CLASS_NAVAL" Name="LOC_UNIT_BIREME_NAME" Description="LOC_UNIT_BIREME_DESCRIPTION" PurchaseYield="YIELD_GOLD" PseudoYieldType="PSEUDOYIELD_UNIT_NAVAL_COMBAT" PromotionClass="PROMOTION_CLASS_NAVAL_MELEE" Maintenance="1.5" Combat="25" PrereqTech="TECH_CELESTIAL_NAVIGATION"/>
<Row UnitType="UNIT_DECERES" BaseMoves="2" Cost="180" AdvisorType="ADVISOR_CONQUEST" BaseSightRange="2" ZoneOfControl="true" Domain="DOMAIN_SEA" FormationClass="FORMATION_CLASS_NAVAL" Name="LOC_UNIT_DECERES_NAME" Description="LOC_UNIT_DECERES_DESCRIPTION" PurchaseYield="YIELD_GOLD" PseudoYieldType="PSEUDOYIELD_UNIT_NAVAL_COMBAT" PromotionClass="PROMOTION_CLASS_NAVAL_RANGED" Maintenance="4" Combat="40" RangedCombat="30" Range="2" PrereqTech="TECH_SHIPBUILDING"/>
<Row UnitType="UNIT_HERBALIST" BaseMoves="2" Cost="60" AdvisorType="ADVISOR_CONQUEST" BaseSightRange="2" ZoneOfControl="false" Domain="DOMAIN_LAND" FormationClass="FORMATION_CLASS_SUPPORT" Name="LOC_UNIT_HERBALIST_NAME" Description="LOC_UNIT_HERBALIST_DESCRIPTION" PurchaseYield="YIELD_GOLD" PromotionClass="PROMOTION_CLASS_SUPPORT" Maintenance="2" PrereqTech="TECH_HERBALISM"/>
<Row UnitType="UNIT_HORSE_ARCHER" BaseMoves="4" Cost="100" AdvisorType="ADVISOR_CONQUEST" BaseSightRange="2" ZoneOfControl="false" Domain="DOMAIN_LAND" FormationClass="FORMATION_CLASS_LAND_COMBAT" Name="LOC_UNIT_HORSE_ARCHER_NAME" Description="LOC_UNIT_HORSE_ARCHER_DESCRIPTION" PurchaseYield="YIELD_GOLD" PromotionClass="PROMOTION_CLASS_RANGED" Maintenance="2" Combat="10" RangedCombat="25" Range="1" PrereqTech="TECH_SADDLES" />
<Row UnitType="UNIT_LIBURNA" BaseMoves="4" Cost="100" AdvisorType="ADVISOR_CONQUEST" BaseSightRange="2" ZoneOfControl="true" Domain="DOMAIN_SEA" FormationClass="FORMATION_CLASS_NAVAL" Name="LOC_UNIT_LIBURNA_NAME" Description="LOC_UNIT_LIBURNA_DESCRIPTION" PurchaseYield="YIELD_GOLD" PseudoYieldType="PSEUDOYIELD_UNIT_NAVAL_COMBAT" PromotionClass="PROMOTION_CLASS_NAVAL_MELEE" Maintenance="2" Combat="28" PrereqTech="TECH_SHIPBUILDING"/>
</Units>
<UnitAiInfos>
<Row UnitType="UNIT_BIREME" AiType="UNITAI_COMBAT"/>
<Row UnitType="UNIT_BIREME" AiType="UNITTYPE_NAVAL"/>
<Row UnitType="UNIT_DECERES" AiType="UNITAI_COMBAT"/>
<Row UnitType="UNIT_DECERES" AiType="UNITTYPE_RANGED"/>
<Row UnitType="UNIT_DECERES" AiType="UNITTYPE_NAVAL"/>
<Row UnitType="UNIT_HERBALIST" AiType="UNITTYPE_SIEGE_SUPPORT"/>
<Row UnitType="UNIT_HORSE_ARCHER" AiType="UNITAI_COMBAT"/>
<Row UnitType="UNIT_HORSE_ARCHER" AiType="UNITTYPE_RANGED"/>
<Row UnitType="UNIT_LIBURNA" AiType="UNITAI_COMBAT"/>
<Row UnitType="UNIT_LIBURNA" AiType="UNITTYPE_NAVAL"/>
</UnitAiInfos>
<TypeTag>
<Row Type="UNIT_BIREME" Tag="CLASS_NAVAL_MELEE"/>
<Row Type="UNIT_DECERES" Tag="CLASS_NAVAL_RANGED"/>
<Row Type="UNIT_HORSE_ARCHER" Tag="CLASS_RANGED"/>
<Row Type="UNIT_LIBURNA" Tag="CLASS_LONGSHIP"/>
<Row Type="UNIT_LIBURNA" Tag="CLASS_NAVAL_MELEE"/>
<Row Type="UNIT_LIBURNA" Tag="CLASS_NAVAL_RAIDER"/>
</TypeTag>
<UnitUpgrades>
<Update>
<Where Unit="UNIT_GALLEY"/>
<Set UpgradeUnit="UNIT_BIREME"/>
</Update>
<Row Unit="UNIT_BIREME" UpgradeUnit="UNIT_LIBURNA"/>
</UnitUpgrades>
</GameInfo>